sailboat horsepower

How to Calculate Outboard Motor Size for Sailboats

It seems so complex to pick the right engine size for your sailboat. I was done with complex calculations and tried to make it easier here.

How to pick the right outboard motor size for your sailboat? To get the right amount of horsepower needed to efficiently propel a sailboat, divide the displacement of the boat (in lb) by 550. You need approximately 1 HP per 550 lb of displacement or 4 HP per 2200 lb. Most sailboats don't need a motor with more than 30 HP.

In this article, I'm talking about small outboard engines for sailboats. We're talking about displacement hulls here, so in other words: keel boats. They need more power than flat bottoms.

But they're not powerboats - so it's not our mission to go fast. It's our mission to get decent speed, good control over the boat, and the best possible fuel efficiency. Without breaking the bank of course.

On this page:

How to pick the right motor size, other factors that are important for size, why is the right motor size important, is there a max hp for sailboats, in conclusion, related questions.

Sailboats need way smaller engines than powerboats. That's great news (unless your ultimate goal is speed), because it's cheaper to buy, cheaper to drive, and cheaper to maintain.

The amount of power you need is related to the hull displacement of your boat.

I like to use the simple formula:

HP = displacement (lb) / 550

So 1 HP for every 550 lb displacement, and 4 hp per 2200 lb.

Here, HP is the amount of horsepower you need to reach the maximum hull speed. This is in optimal conditions. So you have smooth water, no windage, a clean and polished hull, and so on.

If you want to get it absolutely right, you also need to correct for propellor size. And of course, a lot of other factors come into play (more on that later). But generally, these engine sizes will work with the following weights:

That sounds about right to me. But remember that these are all rough estimates: I just try to give you a ballpark figure. There is no one formula to get an exact number. The hull design, sailing conditions, and your personal preference are all very important.

If you're serious about getting a new engine, I definitely recommend to get advice from an expert . But you know, salespeople always recommend the Turbo version. Remember that you don't have to overpower a sailboat. Usually you don't need anything over 30 HP. So at least you now know what will work on average.

What is hull displacement?

• Hull displacement is the weight of the boat, or the amount of water the boat displaces.
• Maximum hull displacement is the weight of the boat when it's fully loaded, including crew.

The weight of the boat is the same as its displacement, because the weight of any object is exactly equal to the weight of the water it displaces (aka: pushes aside). This is called Archimedes Principle.

The weight slightly differs in saltwater from freshwater, because saltwater is heavier. In saltwater, the boat gets a bit lighter. So in theory you can use a smaller engine for a bluewater boat, but in practice this is offset by the stronger current and wind.

How to find the displacement of your boat?

Most manufacturers simply give you the displacement of your boat. If you can't find any data, because, for example, you own an old boat, you can weigh your boat on a truck scale. You can also haul it out and measure it (which is painstaking work).**

Tip: if you're gonna weigh your boat, simply drive it onto a truck scale, and retract the weight of the trailer from the total weight.

Of course, it's not so simple. This formula gives a rough estimate. But for me this was way clearer than all that black magic that I get when I ask people what size engine I should get.

Let's look at the things this formula doesn't take into account.

2-strokes are more powerful than 4-strokes. Two-stroke engines fire once every revolution and four-strokes fire once every other revolution. This makes the 2-stroke twice as powerful. They provide more torque at a higher RPM. But they also wear more quickly. The 4-stroke will last you a lot longer, and its also more fuel efficient.

The right propellor size is just as important as having enough horsepower. With a smaller prop diameter, it has to work harder to generate the same propulsion as a larger diameter. But you can't just go larger always. The prop affects the RPM of your engine, and you have to get in the right range (more on this later). You also have to check the maximum diameter that fits your boat.

Diesels have more torque, because the compression rate is higher than that of gasoline engines. So if you consider a diesel, you can do with less HPs.

High windage hulls (multihulls) need a bit more. A multihull (or larger hull in general) suffers from more friction because of the larger surface. So the engine needs to work a little harder.

If you sail longer distances under power , or against the wind it's a good idea to get a larger engine (but not too large). This helps you to save on fuel since you have lower RPM. Especially if you sail offshore or on open sea. The engine needs to work harder due to stronger wind and current.

If you're just sailing in and out of the marina under power, you may need less HP.

Smooth hull designs need less HPs than bulky hull designs, like the classic wooden clippers and crabbers for example.

It matters to get the right size outboard motor for a couple of reasons.

First of all: smaller engines are cheaper, so you save money on buying the engine.

Secondly: smaller engines use a lot less fuel, so you save money on using the engine.

Thirdly: smaller engines are cheaper to maintain: so you save money on maintenance.

So why not get the smallest engine and get the best fuel economy? There are a couple of advantages to getting a (slightly) bigger engine:

• More power means more control (easier to stop the boat, in case you need to)
• Finding the sweet spot might actually reduce fuel consumption

The sweet spot

To perform optimally, an engine should get up to speed. The problem with an overpowered boat is that the engine won't rev up to 80 - 90% of the RPM. This kills fuel efficiency and also the cooling system won't operate optimally.

• The optimal cruising RPM of the engine is about 85-95% of the maximal RPM
• You should reach cruising RPM at hull speed, so your engine should be at about 90% RPM

The propeller size is very important for the RPM. If your prop diameter is too wide, the engine can't get up to speed and struggles to build power. Bad for fuel economy, bad for the engine, and bad for performance.

On the other hand, if your prop is too small, you don't make use of the engine's full power.

If you struggle to get to high RPM, your prop is too large. If your engine is constantly in the red, you're underpropped.

So don't go too big on the prop, but also don't go too small. The easiest way to get it right is to check the engines manual and see what the manufacturer recommends.

You can definitely go too big on a sailboats engine. An overpowered yacht doesn't make any sense. True, it can look cool, but it can't feel cool. Every displacement hull has a maximum hull speed. That means that it cannot go any faster than the max speed. So if your engine can cruise at that speed, it's not getting any better.

The problem with displacement hulls is that they displace the water, or in other words: they push the water in front of them. They cannot move any faster than they can push away the water. And because the resistance increases as speed increases, there's an absolute, physical speed limit for each keelboat.

That's why powerboats have to get out of the water to reach top speed.

Fun fact: the longer your boat, the higher the hull speed. Want to know the maximum hull speed for your boat? You can find it in this article .

So, you can't go faster than your maximum hull speed, so a 50+HP engine is kind of ridiculous. Bear in mind that a large engine also has the following disadvantages:

First of all: larger engines are more expensive, so you spend more money when buying the engine.

Secondly: larger engines use a lot more fuel, so you spend more money when using the engine.

Thirdly: larger engines are more expensive to maintain: so you spend more money on maintenance.

Also, if your engine is too big, it doesn't reach the optimal cruising RPM, so your fuel economy also gets really bad FAST.

I suggest getting the smallest possible engine that gets you to maximum hull speed while it's at roughly 90% of the RPM. As long as it gives you enough control and good handling, it will get you there. If you give up on going fast, you can actually get really good fuel economy and your engine will last you probably 20 years.

If you want to go fast, a sailboat is not the right one for you. You should instead get a powerboat.

I'm just kidding. Read my 13 Reasons Why Sailing is Better Than Powerboating here .

Do sailboats have motors? Most sailboats are power assisted boats, which means they have a small auxiliary engine to cruise in light air. When a sailboat is sailing under engine power, it is considered a motorboat and it doesn't have right of way.

Thanks for answering my questions.

Taylor Bishop

Thanks for explaining how you can figure out what size you need for an outboard motor. You mentioned that you should find the displacement by weigh a boat on a truck scale. I’m interesting to learn if you need to regularly weigh it in case the hull displacement could change or if it will always be consistent.

Shawn Buckles

Hi MitI, you’re welcome, my pleasure.

Hi Taylor, my pleasure.

You don’t need to weigh your boat regularly, as the hull displacement will stay consistent. You could literally see the hull displacement as the amount of space your hull takes up in the water. So as long as you don’t make any major changes to the hull shape or ballast of your boat, you should see no differences in displacement.

Roger S Johnson

How do you measure for shaft size, most outboard motors are for flat bottom and say measure to the bottom of the boat, most sailboats tapper to the aft. Where do you measure for a tapered bottom sail boat?

Will a 5 horse Honda 4 stroke be ok for a 25 foot Pearson Commander sail boat. Thanks for your time Luke

I think it would be Luke.

Great post, thanks for the info. A naive question from a soon-to-be sailor: I’m considering buying a 28 ft sailboat, with 2500 kg (ca. 5500 lbs) displacement. The engine is in pretty good condition, but is old and the original one (from 1977!), so I am also thinking of an alternative scenario in which it fails. I know that in my area replacing an inboard engine will cost double the price I’m putting down for the boat, and since I’m on a budget, that simply won’t be an option and outboards seem to be cheaper. So the question is: is it possible to put an outboard engine on all boats? Is there some factor that would make it impossible to mount an outboard engine on the boat? Thanks!

Garth Powelson

What is minimum length that a sailboat can go without an outboard. Does a 29’ “require by law” to have engine?

Hello Mr. Buckles, Thanks for the informative article. I’m looking to get the smallest possible outboard for my 1.5 ton displacement fiberglass monohull Hood 23’ sloop. Can I get away with a 4HP?!? What size prop would I need?!? (I’m only going to use it when there is NO wind, and, if I can stay 4HP or below, I am not required to register my vessel—which is pretty cool, so here’s hoping!)

Thanks again, Ship

Hi, I’ve got a older Pearson 39’ . I’m looking to remove the old 40 ho westerbeke and go electric. Unsure of what hp is going to be needed?

emilio h javier

i am purchasing a catalina 22 ft. i have in mind a 4 HP motor. what would be the length of the shaft.

I am considering buying a 25 ft sailboat with a 7200 lb displacement. The boats top speed is listed at 7knots per hour but the diesel motor does not work. The owner has a 9.9hp outboard that can be purchased with the boat. Is 9.9hp enough to power the boat to at least 5 to 6 knots per hour? Thanks. Rick

What weight outboard would be too much for a 20’ Santana, displacement 1,350 lbs? I don’t want too much weight at the back. I want the boat to be seaworthy.

I have not seen this amount of BS in years :) I’m not a marine engineer, yet physicist & avation engineer. You even can’t tell the difference between mass of the vessel and diplacement :D Fcking genius.

Leave a comment

You may also like, life-expectancy-of-marine-diesel-engine.

How Much Fuel Does a Sailboat Use?

How Often Should You Antifoul a Boat?

3 Ways to Convert Your Winches to Self-Tailing

Own your first boat within a year on any budget.

A sailboat doesn't have to be expensive if you know what you're doing. If you want to learn how to make your sailing dream reality within a year, leave your email and I'll send you free updates . I don't like spam - I will only send helpful content.

Ready to Own Your First Boat?

Just tell us the best email address to send your tips to:

Boat-Specs.com

Sailboat specifications.

Sailboat-Data

Sailboat specifications.

There are 188 sailboats on Sailboat-Data.

The Best Outboard Motor for a Sailboat

Last Updated by

Daniel Wade

June 15, 2022

The technology of sailing has remained mostly unchanged for centuries. Since learning to harness the power of wind, sailors have been transiting the world’s oceans, expanding trade routes and exploring new cultures. Although nothing more than a renewable natural resource and a single sail is needed to move a sailboat along the water, there are times when it’s important (and in our modern age, convenient) to leverage off a motor to get you where you need to go.

Like any unique piece of equipment in the world of sailing, outboard motors come in a variety of sizes with features and options to fit any owner’s needs. But of course, one size doesn’t fit all. Every boat is different – even those that come off the production line at the same time – and every owner is looking for something specific when it comes to their sailboat. From the purpose of owning the boat (blue water sailing vs. racing) to the location and impact on maintenance (cold weather vs. tropical weather), an outboard motor is just one of the many elements that will define a sailboat’s function and performance.

Whether you’re a new owner, or a veteran sailor, it’s important to know the basic components of any outboard motor . You should also have an idea of what you want your outboard motor to do for your size and model sailboat.

Table of contents

Outboard Motor Size

A larger boat doesn’t necessarily mean a larger motor. Although there are different ratings for different classes of boats, a small power plant can be more effective than a larger one. Conversely, an outboard motor can easily overpower a small boat and create unsafe conditions at high speeds. Guidelines and requirements differ between motorboats and sailboats. And while there is some overlap, these considerations apply directly to sailboats.

Engine power has to do with how much water a boat displaces. For sailboats, smaller is better. If you’re a bit of a math geek, the exact formula is 4 horsepower for every 2200lb of weight. Coupled with a propeller size, which can be determined using a propeller calculator , you’ll get a rough estimate to use as a guideline to start shopping. This is a good first step, since size is essentially a fixed variable. Though it’s worth noting for those who are buying a sailboat directly from the manufacturer, that actual weight will increase after delivery – once all other rigging and outfitting has been completed.

Physical size of your outboard motor is an important consideration and is directly related to the design of your sailboat. An outboard motor is made up of three parts from top to bottom:

• The Powerhead – Houses the engine. The bulbous part of the motor.
• The Midsection – Houses the exhaust system. Varies in length and design.
• The Lower Unit – Propellers attach to the gearbox. Submerged when operational.

Shaft length is an important design element and should be considered when purchasing a motor. A shaft that is too short will obviously prevent the propeller from being submerged in water, while a shaft that is too long will extend the propellers too far. Not only will it decrease the efficiency of your engine, it will create unnecessary drag. Know your transom length when looking at different models.

When an outboard motor is not being used, it should be stowed in its upright position. Some of the larger motors have an automated switch that will raise it out of the water, but some must be secured manually. Make sure everyone who sails with you is capable of lifting and securing the motor out of the water in case of an emergency.

Outboard Motor Power

Any kind of motor installed on a sailboat (inboard or outboard) should be viewed as a tool to help with maneuvering. Although there are some very skilled sailors out there who can sail into their slip without the aid of a motor, many harbors have restrictions that either don’t allow for the use of full sails, or there simply isn’t enough room to maneuver. A motor with both forward and reverse gears helps tremendously with docking.

While there is no exact correlation between boat length and total weight, the following is a rough guideline:

• 1-4 HP for boats up to 20’ (approximately 1000-2000lbs)
• 4-18 HP for boats between 20-30’ (approximately 2,000-10,000lbs)
• 18-34 HP for boats between 30-40’ (10,000lbs or more)

There are some things to consider when deciding how much horsepower you need or want. Location and the type of conditions you expect you’ll be sailing in is one of the biggest factors. Heavy seas and high winds typically associated with open ocean sailing will put more strain on your engine, and in some cases overpower it, whereas an engine that is heavier than needed will add unnecessary weight when racing. If you plan on motoring for long distances, consider purchasing an engine that will stand up to a lot of use.

Less HP is required for:

• Boat Design – Single hull boats made out of fiberglass require less power.
• 2-Stroke Engines – This is due to an overall lighter weight engine and higher torque.
• Diesel Engines – Diesel delivers more torque because the rate of compression is greater.
• Bigger Propellers – More surface area means more water displacement.
• Location – Motoring on lakes and rivers requires less power than open ocean.
• Distance – A smaller engine is suitable for shorter distances.

More HP is required for:

• Boat Design – Catamarans and heavier boats (regardless of size) require more power.
• 4-Stroke Engine – Engine weight and an extra step of compression yields less power.
• Gas Engines – The rate of compression for gas engines is much lower than diesel.
• Smaller Propeller – A smaller propeller displaces less water.
• Location – Open ocean, with tides and currents, will strain a smaller engine.
• Distance – Cover more distance when wind conditions are poor requires a larger engine.

Outboard Motor Cost

There is no way to quantify how much you will pay for any given motor. But there are several costs associated with owning an outboard motor that are definitely worth considering when making your purchase.

Certainly, a lager, more-powerful engine is going to be costlier than a smaller engine with lower horsepower. But as mentioned earlier, size is not necessarily a guarantee of performance and efficiency. At the same time, there’s only so much you can get out of an engine before you exceed its capability. Larger engines tend to help with resale value should you choose to sell your boat at some point, but a boat outfitted with right motor to begin with will always perform better than a motor that’s large just for the sake of it.

Factor in maintenance costs and fuel when looking at models. You want to run your engine at around 90% of its max RPMs to balance proper fuel usage and with wear and tear. Making a few calls to marine mechanics to inquire about an engine you’re interested in will give you a lot of information a sales person won’t be able to give you. The good news about outboard motors is that most of them are portable, which means you won’t have the added cost of either paying a mechanic to come to you, or having to get your boat to the yard, which usually requires help from a very good friend willing to spend all day driving and sailing back and forth.

Owning a boat requires constant care and maintenance, so a little knowledge goes a long way. While an outboard motor is not required for sailing, it’s a convenient addition that can greatly increase your enjoyment out on the water. Being patient and spending time researching engines will not only help you make the correct purchase but will help you take advantage of a great deal when it presents itself. Whether you sail the Caribbean, or race off the coast of California in a catamaran, there is an outboard motor that’s just right for you.

Related Articles

I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing.

by this author

Sailboat Upgrades

Most Recent

What Does "Sailing By The Lee" Mean?

October 3, 2023

The Best Sailing Schools And Programs: Reviews & Ratings

September 26, 2023

Important Legal Info

Lifeofsailing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies.

Similar Posts

How To Choose The Right Sailing Instructor

August 16, 2023

Cost To Sail Around The World

May 16, 2023

Small Sailboat Sizes: A Complete Guide

October 30, 2022

Popular Posts

Best Liveaboard Catamaran Sailboats

December 28, 2023

Can a Novice Sail Around the World?

Elizabeth O'Malley

4 Best Electric Outboard Motors

How Long Did It Take The Vikings To Sail To England?

10 Best Sailboat Brands (And Why)

December 20, 2023

7 Best Places To Liveaboard A Sailboat

Get the best sailing content.

Top Rated Posts

Lifeofsailing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies. (866) 342-SAIL

© 2024 Life of Sailing Email: [email protected] Address: 11816 Inwood Rd #3024 Dallas, TX 75244 Disclaimer Privacy Policy

• BOAT OF THE YEAR
• Newsletters
• Sailboat Reviews
• Boating Safety
• Sailing Totem
• Charter Resources
• Destinations
• Galley Recipes
• Living Aboard
• Sails and Rigging
• Maintenance
• Best Marine Electronics & Technology

How Sailboats Measure Up

• By By Jeremy McGeary
• Updated: October 17, 2012

Sailboats by the Numbers

Boat reviewers rely on numbers to describe some of the key attributes of their subjects, such as length, beam, draft, and displacement. And while judgments on interior layouts and decor are subjective, these figures describing dimensions are not. There are, however, other numbers commonly cited in spec boxes that can prove more elusive, since they attempt to put a numerical value on how a sailboat might be expected to perform while under way. The commonly used ratios are sail area to displacement (SA/D), displacement to length (D/L), and ballast to displacement (B/D). And though they’re so commonly used that a certain amount of dogma has accrued around them, these figures can, in fact, be misleading, or at least misunderstood. And the result is that a boat can be assigned attributes based on numerical values that don’t take into account how sailboat design has changed over the past several decades.

Here, then, is a look at those ratios, what they attempt to describe, and how they should be interpreted when you go off exploring new and used models. (Click to page 2 for a more in-depth explanation.)

Sail Area/Displacement (SA/D)** An automobile buff seeking a high-performance ride looks for a high power-to-weight ratio and compares the horsepower/curb-weight ratios of different cars. For a sailboat, the SA/D provides the same metric. The horsepower comes from the wind on the sails and is proportional to the sail area; a boat’s weight is its displacement (in pounds, kilograms, or tons).

Initially, the SA/D only really gives a measure of potential acceleration rates (in case any physicists are reading this), but since displacement is a key factor in the resistance a boat encounters when moving through the water, SA/D also has a bearing on potential maximum speed.

The traditional calculation for SA/D compares sail area in square feet to displacement in cubic feet. In the formula, displacement in pounds is divided by 64 (the density of seawater) to obtain cubic feet, which are in turn converted to square feet to make the ratio unit-free.

On a spreadsheet, the formula would be S/(D/64) (2/3).

Nominally, the higher the SA/D, the more lively the boat’s sailing performance. The vessel will accelerate more quickly and have the potential for higher speed. But to be able to compare boats with any degree of precision (or fairness), we have to use similar numbers. The displacement must be in the same condition, either light ship (nothing on board) or fully loaded, and the sail-area measurement must reflect the normal working sail plan. Racing boats have measurement certificates from which these numbers can be reliably extracted. The specifications provided in cruising-boat brochures might not be consistent between builders, but we have to assume they are.

Boats measured in the 1970s and the 1980s for racing under the International Offshore Rule for the most part had SA/Ds between 16 and 17, based on the sum of the mainsail triangle (M = P E/2) and 100-percent foretriangle area (100%FT = I J/2). The measurement system favored small mainsails and large headsails, and since designers of cruising boats stuck close to the IOR sail plan, the IOR value for SA/D became the yardstick. An SA/D above 17 said “fast boat,” and anything below 16 said “slow boat.”

After the IOR fell out of favor, cruising-boat design drifted away from raceboat design, and sail plans began to change. Today, many boats are designed with large mainsails and small jibs, and most builders publish a “total sail area” number that includes the standard jib (often as small as 105 percent) and the roach in the mainsail (which is significantly greater on modern boats with full-battened mainsails than on IOR boats).

These builder-supplied numbers are more readily comparable against competing models, but using them in the SA/D formula makes the boats look “faster” than older models. This is a false comparison, because the sail area used for the older boats doesn’t include the extra area in, say, a 150-percent genoa.

The table “Sailboats by the Numbers” (see page 79) illustrates this. It shows SA/Ds calculated for a selection of modern boats and boats from past eras, all about the same length, using different numbers for sail area. For each model, it shows five SA/Ds. SA/D 1 is calculated using the sail area provided by the builder. SA/D 2 is calculated using M (P E/2) and 100% FT (I J/2). SA/D 3 is calculated using M + 105% jib. SA/D 4 is calculated using M + 135% jib. SA/D 5 is calculated using M + 150% jib. The only SA/D that includes mainsail roach is SA/D 1.

Let’s look at some examples. The 1997 Beneteau Oceanis 411 has a published sail area of 697 square feet on a displacement of 17,196 pounds. That gives an SA/D 1 of 16.7 (the same as SA/D 2), which for decades was considered very respectable for a cruising boat.

In 2012, the current Beneteau Oceanis 41 has a published sail area of 902 square feet (453 mainsail + 449 jib) and a published displacement of 18,624 pounds, to give an SA/D 1 of 20.5. Wow! Super-high performance! But this is for the standard sail area, with the 449-square-foot jib (just about 100% FT and typical of the trend today toward smaller jibs that tack easily). Plug in the calculation using I, J, P, and E and SA/D 2 drops to 18.9 because it doesn’t include mainsail roach, which is about 16 percent of the total published mainsail area.

Go back to the 1997 model, tack on a standard-for-the-day 135-percent genoa, and the SA/D 4 becomes 20.7. (If we added in mainsail roach, typically about 11 percent of base mainsail area before full-battened sails, we’d have 21.4.) The 1997 boat has essentially the same horsepower as the 2012 model.

Looking at current models from other builders, the SA/Ds based on published numbers hover around 20, suggesting that designers agree on the horsepower a cruising sailboat needs to generate adequate performance to windward without frightening anyone.

The two boats in our chart that don’t at first appear to fit this model are the Hunter 39 and the Catalina 385, but they’re not really so far apart.

The Hunter’s SA/D 2 is 16.1. Its standard jib is 110 percent (327 square feet), and the rest of the published sail area is in the mainsail—664 square feet, of which 37 percent is roach!

Catalina is a little more traditional in its thinking. If you add the standard 135-percent genoa, the SA/D becomes 21.2—right in the ballpark. (It’s still there at 19.7 with a 120-percent genoa.)

The table shows that, for boats targeted at the “performance cruising” market, the SA/D numbers using actual sail area lie consistently around the 20 mark. To go above that number, you have to be able to fly that sail area without reefing as soon as the wind ripples the surface. To do that, you have to elevate stability—with broad beam, lightweight (i.e., expensive) construction, deep bulb keels, and fewer creature comforts.

Displacement/Length (D/L)** While sailboat builders and buyers are interested in displacement in terms of weight, naval architects view it as volume; they’re creating three-dimensional shapes. When working in feet, to get a displacement in pounds, they multiply cubic feet by 64, the density in pounds per cubic foot of seawater. (Freshwater boats displace more volume because the density of fresh water is only 62.4.) The D/L ratio is therefore a measure of immersed volume per unit of length—how tubby the hull is below the waterline.

According to conventional wisdom and empirical studies, the lower the D/L, the higher the performance potential. This is mainly due to wavemaking resistance being lower for slender hulls than for tubby hulls.

In the D/L formula, displacement in pounds is divided by 2,240 to convert it to tons to bring the values to manageable numbers, so D/L is displacement in tons divided by .01LWL (in feet) cubed.

In a spreadsheet, the formula would be D/(2240*(.01L)3), where D is the displacement in pounds and L is LWL in feet.

In the early days of fiberglass boats, the Cruising Club of America rule was the principal dictator of boat shapes. Because it was a waterline rule, designers kept waterlines short to keep ratings low and relied on long stern overhangs immersing to add “sailing length” when the boats heeled. Carbon fiber was available only to NASA, and boats had full interiors, so “light displacement” wasn’t really in the cards. A D/L of 300 was considered dashing, even risky. Many still-popular designs from the 1970s and 1980s have D/Ls as high as 400; see the Bounty II.

Fast-forward 40 years. Boats now have plumb bows and plumb sterns and waterlines almost as long as their LOAs—there are no rating penalties on a cruising boat. The boats’ weights haven’t changed much because, although builders try to save weight to save cost, the boats are so much bigger. The hull and deck surface areas are greater, and all that extra internal volume can be filled with furniture. The effect on D/L ratios has been drastic—just look at the table. A D/L ratio above 200 today describes a heffalump.

But do these lower D/Ls actually buy you any more speed? Yes and no.

Yes : Because speed is proportional to the square root of the waterline length. Today’s 40-footer has a much longer waterline than yesterday’s and ought to sail as fast as yesterday’s 50-footer. It might also benefit from reduced resistance due to a smaller cross-sectional area, but it also might have greater wetted-surface drag due to the longer immersed length. When sailing downwind in waves, though, the lower-D/L boat will surf more readily.

No : Because, as we saw above, the power-to-weight ratios (SA/D) of modern boats aren’t effectively any higher, and certainly aren’t in the realm that would allow our cruising sailboats to climb out of the displacement zone and plane. In most conditions, the lower-D/L boat is still trapped in its wave.

In the days of the IOR, a D/L of 250 was still pretty racy; see the 1978 Catalina 38. Today, even a D/L as low as 150 doesn’t make a boat a speedster if it can’t carry the sail area to make it so. To compete at a level with a Volvo 70, look for a D/L of about 40 and an SA/D of 65.

Ballast/Displacement (B/D)** The ballast/displacement ratio is simply the ballast weight divided by the boat’s total displacement. Since ballast is there to give the boat stability, it’s easy to jump to the conclusion that the higher the B/D, the stiffer the boat.

However, B/D doesn’t take into account the location of the ballast.

Take a boat that has a total displacement of 20,000 pounds and put its 8,000 pounds of ballast in the bilge. Now take the same boat and put the 8,000 pounds of ballast 4 feet deeper in a bulb at the bottom of a deep fin keel. Same ballast ratio (0.4), but very different stability.

When looking at B/D, therefore, we must ask about the configuration of the keel: How low is the ballast?

Stability analysis is complex and involves beam, hull cross-section, and length, among other factors, of which B/D is just one.

Since the late 1990s, builders of sailboats intended for sale in the European Union have been required to provide stability data, including a curve of righting arm at angles of heel from 0 to 180 degrees—far more information than anyone can divine from a B/D number and a much more useful measure of a boat’s inclination to stay upside down in the unlikely event (the way most people use their boats) that it exceeds its limit of positive stability.

CW contributing editor Jeremy McGeary is a seasoned yacht designer who’s worked in the naval-architecture offices of David Pedrick, Rodger Martin, and Yves-Marie Tanton and as a staff designer for Camper & Nicholson.

To read the related article, How To: Measure Sail Area, click here.

• More: boat design , How To
• More How To

3 Clutch Sails For Peak Performance

It’s Time to Rethink Your Ditch Kit

8 Ways to Prevent Seasickness

How To De-Winterize Your Diesel Engine

Bitter End Expands Watersports Program

Sailboat Review: Tartan 455

Miracle in a Bowl

Cole Brauer Completes the Global Solo Challenge

• Digital Edition
• Customer Service
• Privacy Policy
• Email Newsletters
• Cruising World
• Sailing World
• Salt Water Sportsman
• Sport Fishing
• Wakeboarding

• Compare Sailboats
• Sailboat Calculators

Bluewater Sailboats

• Catamarans and Multihulls
• Sailing Liveaboard
• Sailboats Galley
• How Much it Costs
• Sailing Destinations
• Meteorology Terms
• Sailing and Nautical Terms
• Parts of a Sailboat
• Great Explorers
• People of the Seas

Oceanwavesail.com is the biggest sailboat data website you can find. It is also the most accurate, as we constantly review and update sailboat data and verify them manually, one by one. New boats are added every month. 

We add new pages every week and new sections on a regular basis, so that you can find all you need in one place, and can rely on it.

If you are passionate about sailing boats, living aboard, looking to find your next dream, this is the place for you, and we hope you will find it easy to navigate and useful.

Sailboat Galley and Recipes

Sailboat data in detail, sailboat ratio calculator, sailboat builders, sailing terminology, great explorers &tall ships, history & more, meteo terminology.

6 Ways and Resources of Boat Tracking

Sailing is a thrilling activity since it gives one a sense of freedom and adventure. The open water beckons with its promise of exploration and discovery, whether you’re taking a coastal cruise or setting out

How to Buy the Best Beginner Sailboat?

Sailing is an alluring activity because it offers the possibility of independence on the broad sea and the rush that comes from using the wind. You’re in for a gratifying experience if you’ve made the

Navigational Charts – How to read them?

The unsung heroes of every sailor’s voyage are their navigational charts. These painstakingly drawn waterway maps serve as the foundation for safe and effective sailing. Learning to read navigational charts is essential whether you’re cruising

How to Anchor a Boat?

One of the key abilities you must acquire before setting sail on your boat, whether it’s for a weekend getaway or a long-distance trip, is how to anchor a boat. While you’re out on the

Sailing Basics: Practical Steps to Learn Sail

Are you attracted to the sea’s call, seduced by the prospect of sailing into the distance, and enthralled by the sailing lifestyle? If so, you are not by yourself. Many people have this dream in

Cruising Lifestyle – Expectations vs. Reality

For many people, living the ocean cruising lifestyle is the ultimate goal. It’s difficult to resist the sense of adventure and freedom that comes with the thought of setting sail across azure oceans, discovering far-off

Subscribe to our newsletter

Don’t miss new updates on your email.

© OceanWave Sail. All Rights Reserved 2022

Terms & Conditions – Privacy Policy – Cookie Policy

About Us – Privacy Policy

• New account

Forgot your password?

Lost your password? Please enter your email address. You will receive mail with link to set new password.

Back to login

Privacy Overview

SAILING THE WEB

The ultimate sailboat database, most popular sailboats.

Legendary sailboats

Last updated sailboats

Sailboat data sheets

On this website you will find many datasheets of the main mass-produced sailboat models : they are informations and contents found by passion over many years of research and checks on the net. Now this archive is free for you to consult and compare various sailboats, create a list of your favorite sailboats and much more: we are just at the beginning!

Use the dedicated section for questions and answers too!

Take advantage of our space reserved for questions and answers! you have an entire community at your disposal from which you can ask for advice, request information on the boat you own or want to discover.

• Types of Sailboats
• Parts of a Sailboat
• Cruising Boats
• Small Sailboats
• Design Basics
• Sailboats under 30'
• Sailboats 30'-35
• Sailboats 35'-40'
• Sailboats 40'-45'
• Sailboats 45'-50'
• Sailboats 50'-55'
• Sailboats over 55'
• Masts & Spars
• Knots, Bends & Hitches
• The 12v Energy Equation
• Electronics & Instrumentation
• Build Your Own Boat
• Buying a Used Boat
• Choosing Accessories
• Living on a Boat
• Cruising Offshore
• Sailing in the Caribbean
• Anchoring Skills
• Sailing Authors & Their Writings
• Mary's Journal
• Nautical Terms
• Cruising Sailboats for Sale
• List your Boat for Sale Here!
• Used Sailing Equipment for Sale
• Sell Your Unwanted Gear
• Sailing eBooks: Download them here!
• Your Sailboats
• Your Sailing Stories
• Your Fishing Stories
• Advertising
• What's New?
• Chartering a Sailboat
• Cruising Yachts 30' to 35'
• Hunter 31 Sailboat

The Hunter 31 Sailboat Specs & Key Performance Indicators

The Hunter 31, a B&R rigged masthead sloop, was designed by Cortland Steck and built in the USA by Hunter Marine.

Published Specification for the Hunter 31

Underwater Profile:  Fin keel & spade rudder

Hull Material:  GRP (Fibreglass)

Length Overall:  31'4" (9.6m)

Waterline Length:  26'3" (8.0m)

Beam:  10'11" (3.4m)

Draft:  5'3" (1.6m)

Rig Type:  B&R

Displacement:  9,700lb (4,400kg)

Ballast:  4,000lb (1,814kg)

Designer:  Cortland Steck

Builder:  Hunter Marine (USA)

Year First Built:  1983

Year Last Built:  1987

Published Design Ratios for the Hunter 31

Sail Area/Displacement Ratio :  16.2

Ballast/Displacement Ratio:  41.2

Displacement/Length Ratio: 239

Comfort Ratio:  22.4

Capsize Screening Formula:   2.1

Read more about these  Key Performance Indicators...

Summary Analysis of the Design Ratios for the Hunter 31

1. A Sail Area/Displacement Ratio of 16.2 suggests that the Hunter 31 will, in the right conditions, approach her maximum hull speed readily and satisfy the sailing performance expectations of most cruising sailors.

2. A Ballast/Displacement Ratio of 41.2 means that the Hunter 31 will stand up well to her canvas in a blow, helping her to power through the waves.

3. A Displacement/Length Ratio of 239, tells us the Hunter 31 is a moderate displacement cruiser, which means she'll carry all your cruising gear without it having a dramatic effect on her performance. Most of today's sailboats intended for offshore cruising fall into this displacement category.

4. Ted Brewer's Comfort Ratio of 22.4 suggests that crew comfort of a Hunter 31 in a seaway is similar to what you would associate with the motion of a coastal cruiser with moderate stability, which is not the best of news for anyone prone to seasickness. 

5. The Capsize Screening Formula of 2.1 tells us that a Hunter 31 would not be as good a choice of sailboat for ocean passage-making, owing to the increased risk of capsize in strong winds and heavy seas when compared to a sailboat with a CSF of less than 2.0.

The Hunter 31 Sailboat: A Review

The Hunter 31 is a popular model from Hunter Marine, an American company that has been building quality sailboats since 1973. The Hunter 31 was first introduced in 1983 and was designed by Cortland Steck. It was produced until 1987, when it was replaced by the Hunter 33.5. In 2006, Hunter Marine launched a new version of the Hunter 31, which is sometimes referred to as the Hunter 31-2 or the Hunter 30/31. This boat was designed by Glenn Henderson and was in production until 2014. In this article, we will focus on the original Hunter 31, but we will also mention some of the differences and similarities with the newer model.

The Hunter 31 is a sloop-rigged cruiser that can accommodate up to six people in two cabins and a convertible salon. It has a fin keel, a spade rudder and a single wheel steering system. The boat has a self-tacking jib and an optional in-mast furling system for easy sail handling. The boat also has a Yanmar diesel engine with a low fuel capacity of 12 gallons.

The Hunter 31 is a boat that offers a lot of features and benefits for recreational sailors. Here are some of the main aspects of the boat that you might want to know more about:

Overview The Hunter 31 is a boat that combines performance, comfort and convenience. It is a boat that can sail well in light to moderate winds, thanks to its efficient hull shape and rig design. It is also a boat that can handle rougher conditions, thanks to its high stability and stiffness. The boat has a PHRF rating of 174, which means it is faster than some of its competitors in its size range.

The Hunter 31 is also a boat that offers plenty of space and amenities for living aboard. It has a beam of 10 feet and 11 inches, which gives it a roomy interior and a wide cockpit. It has two private cabins, one forward and one aft, each with a double berth and storage space. It has a large salon with a U-shaped dinette that can convert into another double berth, a navigation station with an electrical panel and instruments, and a galley with a two-burner stove, an oven, a sink, an icebox and ample counter space. It has a head with a marine toilet, a sink and a shower. It also has plenty of ventilation and natural light, thanks to its numerous ports, hatches and skylights.

The Hunter 31 is also a boat that is easy to operate and maintain. It has a simple and user-friendly layout, with all the controls and lines led back to the cockpit. It has an engine access panel under the companionway steps, which makes it easy to check and service the engine. It has a molded fiberglass hull and deck, which are durable and easy to clean.

Accommodation The Hunter 31 can sleep up to six people in two cabins and a convertible salon. The forward cabin has a V-shaped double berth with storage drawers underneath, shelves along the hull sides, an overhead hatch and two opening ports. The aft cabin has an athwartships double berth with storage lockers underneath, shelves along the hull sides, an opening port and an overhead hatch. The salon has a U-shaped dinette that can convert into another double berth with storage lockers underneath, shelves along the hull sides, four opening ports and two overhead hatches. The head is located on the port side of the salon, opposite the galley. It has a marine toilet with a holding tank, a sink with hot and cold water, a shower with a sump pump, storage cabinets, an opening port and an overhead hatch.

The accommodation layout of the newer Hunter 31-2 is slightly different from the original model. The forward cabin has more headroom and more storage space than the original model. The aft cabin has less headroom but more floor space than the original model. The salon has a straight settee on the starboard side instead of a navigation station, and a smaller dinette on the port side that can convert into a single berth. The head is located on the starboard side of the salon, opposite the galley. It has a separate shower stall with a folding door, which makes it more spacious and comfortable than the original model.

Hull and Deck The Hunter 31 has a solid fiberglass hull with a balsa core sandwich construction for the deck. The hull has a moderate displacement of 9,700 pounds and a ballast of 4,000 pounds. The hull has a fin keel with a draft of 5 feet and 3 inches, which gives it good performance and stability. The hull also has a spade rudder with a stainless steel shaft and bearings, which gives it good maneuverability and responsiveness. The deck of the Hunter 31 is designed for safety and convenience. It has a wide and flat foredeck with an anchor locker, an anchor roller and an electric windlass. It has stainless steel bow and stern pulpits, stanchions and lifelines. It has two dorade vents on the cabin top for ventilation. It has two large cockpit lockers for storage, one on each side of the wheel. It has a transom swim platform with a folding ladder and a shower. It also has a stern rail seat on each side of the cockpit, which provides extra seating and visibility.

The hull and deck of the newer Hunter 31-2 are similar to the original model, but with some improvements and modifications. The hull has a slightly longer waterline length of 28 feet, which increases its speed potential. The hull also has a shoal draft option of 3 feet and 11 inches, which makes it more suitable for shallow waters. The deck has a more modern and sleek appearance, with flush-mounted hatches, recessed handrails and an arch over the cockpit that supports the mainsheet traveler and the optional bimini top.

Mast and Rigging The Hunter 31 has a sloop rig with a deck-stepped mast and swept-back spreaders. The mast is made of anodized aluminum and has internal halyards and wiring. The mast height is 46 feet and 7 inches, which makes it suitable for most bridges and marinas. The mast also has an optional in-mast furling system for the mainsail, which makes it easier to reef and stow the sail.

The boat has a B&R rig, which is a fractional rig that eliminates the need for a backstay. This allows for a larger mainsail area and a smaller jib area, which improves the boat's performance in light winds and reduces its heeling tendency. The boat also has a self-tacking jib, which makes it easier to tack and trim the sail without changing sheets.

The boat has stainless steel standing rigging and low-stretch running rigging. The boat has two Lewmar self-tailing winches on the cabin top for halyards and reefing lines, and two Lewmar self-tailing winches on the coaming for jib sheets. The boat also has rope clutches, cam cleats, blocks, tracks and cars for adjusting the sails. The mast and rigging of the newer Hunter 31-2 are similar to the original model, but with some differences. The mast height is slightly lower at 46 feet, which reduces its windage and weight aloft. The mast also has an optional in-boom furling system for the mainsail, which gives it more sail shape control than the in-mast furling system. The boat also has an optional spinnaker or gennaker for downwind sailing.

Keel and Rudder The Hunter 31 has a fin keel which is bolted to the hull with stainless steel bolts and nuts. The keel draft is 5 feet and 3 inches, which gives it good performance upwind and downwind. The keel also provides stability and balance to the boat. The boat has a spade rudder with a stainless steel shaft and bearings. The rudder draft is 5 feet, which matches the keel draft. The rudder also provides maneuverability and control to the boat.

The keel and rudder of the newer Hunter 31-2 are similar to the original model, but with some options. The boat has a shoal draft option of 3 feet and 11 inches, which reduces its draft by more than one foot. The boat also has an optional wing keel or twin keels, which increase its stability at low speeds or when anchored.

The above text was drafted by sailboat-cruising.com using GPT-4 (OpenAI’s large-scale language-generation model) as a research assistant to develop source material; we believe it to be accurate to the best of our knowledge.

Other sailboats in the Hunter range include:

Recent Articles

'Natalya', a Jeanneau Sun Odyssey 54DS for Sale

Mar 17, 24 04:07 PM

'Wahoo', a Hunter Passage 42 for Sale

Mar 17, 24 08:13 AM

Used Sailing Equipment For Sale

Feb 28, 24 05:58 AM

Here's where to:

• Find  Used Sailboats for Sale...
• Find Used Sailing Gear for Sale...
• List your Sailboat for Sale...
• List your Used Sailing Gear...
• Sign-up for our newsletter, 'The Sailboat Cruiser' ...
• Identify this month's Mystery Boat...

Our eBooks...

A few of our Most Popular Pages...

Copyright © 2024  Dick McClary  Sailboat-Cruising.com

Sail GP: how do supercharged racing yachts go so fast? An engineer explains

Head of Engineering, Warsash School of Maritime Science and Engineering, Solent University

Disclosure statement

Jonathan Ridley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

View all partners

Sailing used to be considered as a rather sedate pastime. But in the past few years, the world of yacht racing has been revolutionised by the arrival of hydrofoil-supported catamarans, known as “foilers”. These vessels, more akin to high-performance aircraft than yachts, combine the laws of aerodynamics and hydrodynamics to create vessels capable of speeds of up to 50 knots, which is far faster than the wind propelling them.

An F50 catamaran preparing for the Sail GP series recently even broke this barrier, reaching an incredible speed of 50.22 knots (57.8mph) purely powered by the wind. This was achieved in a wind of just 19.3 knots (22.2mph). F50s are 15-metre-long, 8.8-metre-wide hydrofoil catamarans propelled by rigid sails and capable of such astounding speeds that Sail GP has been called the “ Formula One of sailing ”. How are these yachts able to go so fast? The answer lies in some simple fluid dynamics.

As a vessel’s hull moves through the water, there are two primary physical mechanisms that create drag and slow the vessel down. To build a faster boat you have to find ways to overcome the drag force.

The first mechanism is friction. As the water flows past the hull, a microscopic layer of water is effectively attached to the hull and is pulled along with the yacht. A second layer of water then attaches to the first layer, and the sliding or shearing between them creates friction.

On the outside of this is a third layer, which slides over the inner layers creating more friction, and so on. Together, these layers are known as the boundary layer – and it’s the shearing of the boundary layer’s molecules against each other that creates frictional drag.

A yacht also makes waves as it pushes the water around and under the hull from the bow (front) to the stern (back) of the boat. The waves form two distinctive patterns around the yacht (one at each end), known as Kelvin Wave patterns.

These waves, which move at the same speed as the yacht, are very energetic. This creates drag on the boat known as the wave-making drag, which is responsible for around 90% of the total drag. As the yacht accelerates to faster speeds (close to the “hull speed”, explained later), these waves get higher and longer.

These two effects combine to produce a phenomenon known as “ hull speed ”, which is the fastest the boat can travel – and in conventional single-hull yachts it is very slow. A single-hull yacht of the same size as the F50 has a hull speed of around 12 mph.

However, it’s possible to reduce both the frictional and wave-making drag and overcome this hull-speed limit by building a yacht with hydrofoils . Hydrofoils are small, underwater wings. These act in the same way as an aircraft wing, creating a lift force which acts against gravity, lifting our yacht upwards so that the hull is clear of the water.

While an aircraft’s wings are very large, the high density of water compared to air means that we only need very small hydrofoils to produce a lot of the important lift force. A hydrofoil just the size of three A3 sheets of paper, when moving at just 10 mph, can produce enough lift to pick up a large person.

This significantly reduces the surface area and the volume of the boat that is underwater, which cuts the frictional drag and the wave-making drag, respectively. The combined effect is a reduction in the overall drag to a fraction of its original amount, so that the yacht is capable of sailing much faster than it could without hydrofoils.

The other innovation that helps boost the speed of racing yachts is the use of rigid sails . The power available from traditional sails to drive the boat forward is relatively small, limited by the fact that the sail’s forces have to act in equilibrium with a range of other forces, and that fabric sails do not make an ideal shape for creating power. Rigid sails, which are very similar in design to an aircraft wing, form a much more efficient shape than traditional sails, effectively giving the yacht a larger engine and more power.

As the yacht accelerates from the driving force of these sails, it experiences what is known as “ apparent wind ”. Imagine a completely calm day, with no wind. As you walk, you experience a breeze in your face at the same speed that you are walking. If there was a wind blowing too, you would feel a mixture of the real (or “true” wind) and the breeze you have generated.

The two together form the apparent wind, which can be faster than the true wind. If there is enough true wind combined with this apparent wind, then significant force and power can be generated from the sail to propel the yacht, so it can easily sail faster than the wind speed itself.

The combined effect of reducing the drag and increasing the driving power results in a yacht that is far faster than those of even a few years ago. But all of this would not be possible without one further advance: materials. In order to be able to “fly”, the yacht must have a low mass, and the hydrofoil itself must be very strong. To achieve the required mass, strength and rigidity using traditional boat-building materials such as wood or aluminium would be very difficult.

This is where modern advanced composite materials such as carbon fibre come in. Production techniques optimising weight, rigidity and strength allow the production of structures that are strong and light enough to produce incredible yachts like the F50.

The engineers who design these high-performance boats (known as naval architects ) are always looking to use new materials and science to get an optimum design. In theory, the F50 should be able to go even faster.

• Engineering
• Aerodynamics

Deputy Editor - Technology

Sydney Horizon Educators (Identified)

Assistant Grants Officer

Deputy Vice-Chancellor (Academic and Student Life)

Visiting Professor - 2024-25 Australia-Korea Chair in Australian Studies at Seoul National University

Search Engines

Applications

Sailboat & small craft, explore yanmar’s common rail engine series.

SETTING THE GLOBAL STANDARD –  YANMAR common rail marine engines set global standards in performance, efficiency, and endurance. Uncompromising in our engineering, we deliver cutting-edge technology as standard across our whole range. We focus on your comfort and safety, and a low total cost of ownership, while delivering outstanding power and speed.

Powered by Yanmar

Common rail technology, 5x best in class, certifications, powered by yanmar.

Sign-up to receive the latest information about new products, services, and general updates.

YANMAR’S extensive global service and parts network spans 130 countries and over 2100 locations.

We’re here to help and would love to hear from you. Contact us with inquiries, comments, and feedback.

Elige tu idioma

Choisissez votre langue, velg ditt språk.

Nederlandsk

Portugisisk

Välj ditt språk

Portugisiska

• New Sailboats
• Sailboats 21-30ft
• Sailboats 31-35ft
• Sailboats 36-40ft
• Sailboats Over 40ft
• Sailboats Under 21feet
• used_sailboats
• Apps and Computer Programs
• Communications
• Fishfinders
• Handheld Electronics
• Plotters MFDS Rradar
• Wind, Speed & Depth Instruments
• Anchoring Mooring
• Running Rigging
• Sails Canvas
• Standing Rigging
• Diesel Engines
• Off Grid Energy
• Cleaning Waxing
• DIY Projects
• Repair, Tools & Materials
• Spare Parts
• Tools & Gadgets
• Cabin Comfort
• Ventilation
• Footwear Apparel
• Foul Weather Gear
• Mailport & PS Advisor
• Inside Practical Sailor Blog
• Activate My Web Access
• Reset Password
• Pay My Bill
• Customer Service

• Free Newsletter
• Give a Gift

How to Sell Your Boat

Cal 2-46: A Venerable Lapworth Design Brought Up to Date

Rhumb Lines: Show Highlights from Annapolis

Open Transom Pros and Cons

Leaping Into Lithium

The Importance of Sea State in Weather Planning

Do-it-yourself Electrical System Survey and Inspection

Install a Standalone Sounder Without Drilling

Rethinking MOB Prevention

Top-notch Wind Indicators

The Everlasting Multihull Trampoline

In Search of the Snag-free Clew

What’s Involved in Setting Up a Lithium Battery System?

Reducing Engine Room Noise

Breaking Point: What Can Go Wrong With Your Yanmar?

Mildew-resistant Caulks for Boats

Can We Trust Plastic Boat Parts?

Repairing Molded Plastics

Mailport: Marine plywood, fuel additives, through bolt options, winch handle holders

The Day Sailor’s First-Aid Kit

Choosing and Securing Seat Cushions

Cockpit Drains on Race Boats

Rhumb Lines: Livin’ the Wharf Rat Life

Safer Sailing: Add Leg Loops to Your Harness

Resurrecting Slippery Boat Shoes

Tricks and Tips to Forming Do-it-yourself Rigging Terminals

Marine Toilet Maintenance Tips

Learning to Live with Plastic Boat Bits

The Ultimate Guide to Caring for Clear Plastic

• Sailboat Reviews

The Hunter 27 is a boat built to a price--a low price--and it shows; but it may represent a good value.

The Hunter 27 is the smallest boat in the Hunter line, which runs up to 43′ in length. The Hunter 27 is a popular boat with first-time sailboat buyers, and with small-boat sailors purchasing their first auxiliary cruising boat. Since the boat was introduced in 1975, thousands have been built.

Like other boats with a reasonably long production run, the Hunter 27 has gone through minor changes since its introduction. Wheel steering is now standard. The boat utilizes a split backstay to allow a stern boarding ladder and to prevent the helmsman from hitting his head on a centerline backstay. All the ports open for ventilation, The mainsheet lead has been altered, and there have been other minor modifications, such as a switch to European-style pulpits and running lights.

Judging from the response of Hunter owners we’ve talked to, all Hunters, including the 27, are purchased for one reason: price. The Hunter 27 is just about the cheapest diesel-powered 27′ cruising boat money can buy.

In their advertising literature, Hunter stresses that efficiency in construction, standardization of components, and low overhead keep their prices low, To some extent, this is true, and it is neither new, nor is it anything to be ashamed of. The Herreshoff Manufacturing Company, known neither for cheap boats nor low quality, pioneered in component standardization and assembly-line construction.

By eliminating factory-installed options, every Hunter 27 can be built the same. No going to the stockroom for an optional item. No time-consuming reading of each boat’s specifications as it moves down the assembly line. There are trade-offs, however.

An inability to custom-tailor a boat. A lack of flexibility in deck layout. The Hunter 27 owner must customize his boat at the dealer level, or do it himself. This appeals to dealers, who often make as much on the installation of options as they do on commissions.

The Hunter 27 is a bit high-sided and sterile looking. High freeboard and a high cabin trunk are almost necessary in a 27, boat that claims over 6′ of headroom. The sterility comes from the Hunter bone white on bone white color scheme, and paucity of external teak trim. Exterior teak is to the fiberglass boatbuilding industry what chrome is to Detroit. There are no hull and deck color options.

Construction

Construction of the Hunter 27 is solid glass layup, with plywood reinforcement in high-stress areas such as winch mountings and locker tops. Gelcoat and finish quality of the hull molding are good. No roving printthrough is evident, and the hull is quite fair—more than can be said for many more expensive boats.

The hull-to-deck joint of the Hunter 27 is simple and strong. The hull molding has an internal flange molded at right angles to the hull at deck level. This flange is heavily coated with adhesive bedding, the deck molding is laid over the flange, and the joint covered with a slotted aluminum toerail which is through-bolted with stainless steel bolts at 6-inch intervals. This is an obvious and very satisfactory answer to the hull-to-deck joint problem. The flaying surfaces of the joint appear to match well, and the adhesive compound has squeezed out along the joint where it can be inspected.

Across the transom, the joint is less satisfactory. The gelcoat and putty with which the joint is faired at the stern was sloppy on every Hunter 27 we examined.

The keel of the Hunter 27 is a narrow, high aspect lead fin weighing 3,000 lbs. The shoal draft version has a much shallower lead fin weighing 3,200 lbs. The additional weight of the shoal keel is to make up for the shift in the vertical center of gravity of the boat that would occur if a shoal keel of the same weight as the deep fin were to be used.

The keel-to-hull joint has caused problems in some Hunter 27s. The narrowness of the lead keel at the point of attachment to the hull results in considerable leverage on the hull when the boat heels. Several Hunter 27 owners who returned The Practical Sailor boat owner evaluations report oilcanning of the hull, leaking keelbolts, or vertical misalignment of the hull and keel. We have observed this vertical misalignment in the Hunter 25, but we have not seen it specifically in the 27.

The chainplates of the Hunter 27 consist of stainless steel U-bolts fastened through the anodized aluminum toerail. No backing plates are used with these. The chainplates are likely to carry any load to which they will normally be subjected. However, a simple U-bolt, no matter how heavy, is a poor choice for a primary chainplate unless the arc of the U-bolt is radiused to the diameter of the clevis pin which goes through it, and unless the strain on the bolt lines up with its vertical axis, U-bolt chainplates of the correct configuration are used in some European boats, notably the Nicholson and Bowman lines. Both of these lines of boats carry Lloyd’s Bureau of Shipping classification certificates. We strongly suggest that Hunter 27 owners consider installing aluminum or stainless steel backing plates under their U-bolt chainplates, and check them periodically to be sure that the nuts are tight. With only two nuts on each shroud anchorage, this check is extremely important.

The rig is a modern, high aspect ratio masthead sloop. The mast is a deck-stepped, white Kenyon spar, supported by a wood compression column attached to the main bulkhead. We have seen no sign of compression stress in the Hunter 27 mast step.

Hunter uses gate valves on underwater skin fittings, We prefer seacocks. We also prefer some kind of shutoff valve on any skin fitting remotely near the waterline. Few builders provide them. Hunter is no exception.

Handling Under Sail

The Hunter 27 comes with a mainsail and 110% genoa. The total sail area with this configuration is 360 square feet, an average amount for a modern 7,000 lb boat. A larger genoa will be required for sailing in light-air areas.

Despite a ballast/displacement ratio of almost 43%, owners do not consider the Hunter 27 a stiff boat under sail. They also consider the boat’s performance under sail only fair to good. There are several reasons for the boat’s mediocre sailing qualities.

First of all, the boat comes factory-equipped with sails. This means cheaper sails, for they are bought in quantity by the builder. It also, almost inevitably, means sails that are not designed for specific local conditions. Average sails make for average performance.

There is no provision for headsail sheeting angle adjustment. Without a genoa track, all headsails must sheet to the slotted toerail. On a wide 27-footer with this arrangement, the headsail slot will rarely be the proper width for good windward performance.

With a small headsail, the lead will almost always be too far outboard.

There is also no traveler for the main sheet. This limits the creation of the proper angle of attack of the mainsail, and complicates draft control.

A relatively fat boat such as the Hunter 27 rapidly acquires weather helm as the boat heels. This is due in part to the asymmetry of the boat’s submerged sections. The judicious use of sail controls such as travelers, vangs, and flattening reefs greatly enhances the ability to keep the boat sailing on her feet, which will help reduce weather helm. Hunter 27 owners complain that the boat suffers from extreme weather helm.

Chainplates set at the outboard edge of the deck also compromise windward performance. This arrangement makes it almost impossible to close the slot effectively with a large headsail.

If the Hunter 27 were equipped with well-made sails, inboard chainplates, inboard and outboard headsail tracks, a good vang, and a mainsheet traveler, we suspect that there would be a substantial improvement in the boat’s windward ability. There would also be a marked difference in price. Should you desire to make these changes, the parts would probably cost upwards of $1,500. Then the problems begin. How do you attach the chainplates? Will the deck take the vertical loading that will be on the track? Can the boom handle heavy vang loads? We are not talking about turning the Hunter 27 into a hot racer. We are only talking about improving the performance of the boat to a reasonable level for cruising.

Windward performance, then, is one of the tradeoffs made for low price. Only the prospective purchaser, after considering how the boat is to be used, can decide how much that is worth. Since the shoal-draft Hunter 27 is more heavily ballasted than the deep-draft version, its stability is likely to be similar. However, the deep, high aspect ratio fin is likely to be more efficient.

Handling Under Power

With only eight horsepower to push around a 7,000 lb, high-sided boat, do not expect a Hunter 27 to be a sprightly performer under power.

In 1979, the power plant of the Hunter 27 was changed from the eight horsepower Renault diesel. The Renault diesels were relatively untried in the US marine market. The early Yanmar engines, though noisy and noted for their vibration, are also known for their reliability.

At least one owner we talked to was, to put it mildly, disappointed with the Renault installation. Although the engine runs well, the attachment of the shifting mechanism to the transmission lever has the disconcerting habit of vibrating itself loose. When docking, the results of this shortcoming could be less than amusing to both the boat owner and his insurance company.

Owners of Renault-powered Hunter 27s should definitely be aware of this potential problem.

Another owner reported leaking strut bolts and shaft wear due to improper shaft alignment, All engine installations should be realigned after the boat is launched for the first time. This should be a routine part of commissioning, but it rarely is. A given used Hunter 27 may not have had it done.

Engine access is good, behind the removable companionway ladder. There is partial soundproofing in the engine enclosure, but not enough to shield the interior from a substantial amount of noise.

Fuel capacity is 12.5 gallons, in an aluminum tank located in the starboard cockpit locker. The tank is held in place by a stainless steel strap, There is no grounding jumper between the fuel fill and the tank. This is in violation of the standards for fuel tank installation of the American Boat and Yacht Council, which sets minimum standards used in the industry.

Owners consider the boat underpowered with either the Renault or Yanmar engines. They consider the boat’s performance under power only fair to good.

Deck Layout

Because the Hunter 27’s decks are relatively free of sail control hardware, there are relatively few toe stubbers. Even the grayest cloud has a silver lining.

New Hunter 27s have international style running lights mounted on the bow and stern pulpits. These are far superior to the in-hull running lights on older Hunters, and better than those used on many more expensive boats. New boats also have a good-sized foredeck anchor well, incorporating a well-designed latch and a heavy stainless steel eye for the attachment of the bitter end of the anchor rode. The well has a large scupper which drains through the stem.

Although owners consider the cockpit of the Hunter 27 small, we find it comfortable for five, and certainly large enough for a 27′ boat. Wheel steering has definitely made the cockpit seem bigger. With five people in the cockpit, the stern of the boat begins to squat. A bigger cockpit would only encourage sailing with more people, causing the boat to squat even more.

Late models have Yacht Specialties pedestal steering. There is good provision for an emergency tiller, which is supplied with the boat.

Access to the steering gear is excellent, through the lazarette locker. Unfortunately, because the steering gear, scupper hoses, and exhaust hose go through this locker, it cannot be used for storage. To do so would be to risk damage to vital parts of the ship’s systems.

There is a large locker under the starboard cockpit seat. Unfortunately, because the fuel tank is located in this locker, nothing can really be stowed there without risking damage to the fuel system. Wet lines or sails stored in the locker would drip on the aluminum tank, inviting corrosion. Shelves installed in both these lockers would make them more useful.

To raise the cockpit sill above the level of the lowest cockpit coaming, the lower drop-board must be left in place, This complicates access below when underway, but having the companionway blocked up to deck level is essential for sailing in unsheltered waters or heavy weather.

The cockpit bulkhead slopes forward. This means that a dodger must be installed if one wishes to ventilate the cabin in rain or heavy weather.

The high cockpit coamings provide good backrests for those sitting in the cockpit. They should also help keep the cockpit dry. These coamings have moldedin sheet winch islands. The owner wishing to upgrade to winches larger than the standard Lewmar 7s will discover that the islands are too small for a much larger winch. For the owner who wishes to use a large genoa, this could be a real problem. Despite these shortcomings, the T-shaped cockpit is reasonably comfortable, and is one of the boat’s better design features.

The Hunter 27 is a roomy boat. Headroom is just over 6′ under the main hatch, and almost 5′ 10″ at the forward end of the main cabin.

The forepeak contains a double berth. Aft of that cabin is a full-width head. Newer Hunter 27s have a holding tank system. Older boats are likely to have portable heads.

The main cabin has settee berths port and starboard. These settees extend under the forward bulkhead. While this arrangement reduces seating area, it also allows more room for the galley and quarterberth. It’s a reasonable trade-off.

To port, at the aft end of the cabin, there is a quarterberth. A folding chart table is located over the forward end of the quarterberth. To starboard is the galley, with sink, two-burner alcohol stove, and icebox.

With eight opening ports, two opening hatches, and the companionway, ventilation in newer Hunter 27s is excellent at anchor in good weather. Older models have fewer opening ports. As with many boats, there is no provision for ventilation in heavy weather.

With a molded glass headliner, teak-finished bulkheads, solid teak trim, and teak cabin sole, the cabin has a finished appearance. There is good storage for a boat of this size for short-term cruising. Joinerwork is of fair stock boat quality.

Conclusions

A new Hunter 27 in the ’80s was about the least expensive boat in its class—far cheaper than many other boats of this size. The boat also comes standard with items that are optional on other boats, such as wheel steering, life jackets, anchor, and fire extinguishers.

However, it is not realistic to expect a boat that is 15% cheaper than another boat of the same size and type to be equivalent in quality. There is just so much that efficiency, standardization, and bulk buying can do toward reducing the price of a boat. Inevitably, the price of a boat is a function the time, materials, and incidental costs that go into it. There is no magic way to reduce the cost of building a boat.

The Hunter 27 graphically demonstrates how costs can be reduced. A great deal of time is saved in construction by hurrying finish work, by using staples instead of screws, by eliminating the necessity to customize each boat.

Hunter owners are the first to admit the influence that the low price of the boat had on their boat-buying decision. Many are happy with their boats, some are defensive about them, and others are really unhappy with them. For the relatively unsophisticated sailboat buyer—the new sailor, the powerboat convert—the Hunter 27 may represent a good value. As his experience grows, we expect he will be willing to pay more, in order to get more.

RELATED ARTICLES MORE FROM AUTHOR

Thank you for this article as I, a novice am about to rehab and deal with a 1978 Hunter. As I go through this I suspect many a sentence will ring in my mind to remind me what an experienced sailor has: time to reflect on learning experiences and sharing it with others. Best Wishes and fair winds – Alex Schult

I have a 1979 Hunter 27 I have completely restored her I re manned a yanmar 20gmf new North Sailes new standing and running rigging keel bolts do not leak self tailing winches yes she is a production boat but points and sails fine for cruising. Interior completely renovated hmmn no staples! I have seen and been on some so called higher end boats quality and preformence is a matter of opinion you need deep pockets for a custom boat if you have the $$$ go for it for me I’ll stick with my Hunter 27 Aura great boat without breaking the bank!😎

Hey Theodore, I’ve owned a 82 Hunter 27’ for over 20 years. I took a job about 5 years ago that included a lot of international travel and found myself using my boat for doc candy and Christmas decorations at our home doc. So, I’m beginning a complete refrub, which includes a new Yanmar motor (ouch). I’ve got quite a bit of interior and exterior rehab with not a lot of experience. Anyway I could pull on some of your experience?

We purchased a 1979 Hunter 27 in 2020 as an upgrade from our Nordica 16. Our territory (the Baie de Chaleurs) in northern New Brunswick Canada has a reputation for unpredictable winds and weather. I installed wheel steering (an Edson outfit) which greatly improved my enjoyment. However, I still has issued with docking using the low-cockpit controls for the Yanmar diesel. Researching for solutions, I came across the website of “Electric Yacht” out of Minnesota. So, in 2021, I converted the drive to electric. It has taken me two years to sell the Yanmar. The conversion cost me around $15,000 CA including 4 hours for a machinist to align the propeller shaft and electric motor properly (the hardest part). We are more than happy with the results. Docking now is a joy. I even learned to back-in to our berth and my eyes are always on my surroundings. All the controls are on my binacle The 10 KW motor uses four 150 AmpHr lithium iron-phosphate batteries and works flawlessly. We have even crossed the bay to Quebec twice under just power alone. No gas, no fumes, no noise. He are happy saiiers 🙂

LEAVE A REPLY Cancel reply

Log in to leave a comment

Latest Videos

Island Packet 370: What You Should Know | Boat Review

How To Make Starlink Better On Your Boat | Interview

Catalina 380: What You Should Know | Boat Review

• Privacy Policy
• Do Not Sell My Personal Information
• Online Account Activation
• Privacy Manager

• Build A Boat
• Find A Dealer

• How Much Horsepower Do I Need for My Boat?

If you’ve been searching for a boat to purchase, or have reached the point at which you’d like to get a new engine, chances are you’ve asked the question, “How much horsepower do I need for my boat?” While the individual concerns may be different — wanting to make sure there’s enough horsepower or not too much horsepower — it’s a question many people who are interested in purchasing a new boat ask.

Sometimes, the follow-up question is, “Is it illegal to overpower a boat?” Whether you’ve been asking yourself one of these questions, or are just curious about how horsepower can affect the cost of fuel and insurance, we’ve gathered several pieces of information to educate you on horsepower. Through reading this information, you’ll be able to learn more about where it came from, how it’s calculated, how to determine the amount you need and the dangers that come with having too much.

What Is Boat Horsepower?

Horsepower is defined as a unit of power equal to 550 foot-pounds per second used to measure the power of an engine. Today, it applies to boat and auto engines, but its original use was to describe the power of a steam engine. In the late 1700s, a Scottish engineer named James Watt invented the first steam engine, which improved on a design  pioneered by Thomas Newcomen in 1712 . It was a big deal. This new steam engine could do the same amount of work as the former Newcomen engine, but used only one-quarter of the fuel.

Unfortunately, comparing the steam engine to the Newcomen engine wasn’t effective marketing, as most of the population was still using horses for mechanical work. To market his new product to this audience, Watt knew he had to come up with a way to compare the work of horses to the work of his invention. Through his experiments, he determined one horse could do about 33,000 foot-pounds of work in one minute — meaning a horse could lift a 33,000-pound weight one foot in one minute. Therefore, he defined one horsepower as 33,000 foot-pounds of work per minute — or 550 foot-pounds per second.

There were a few flaws with this new measurement — the biggest being the assumption that a horse could continue to work at that consistent rate instead of tiring out. However, Watt didn’t let that fact bother him, and it didn’t bother his customers, either. Comparing the power of a horse to the power of a steam engine showed Watt’s steam engine could do the work of five horses, and it went on to become an integral part of the Industrial Revolution.

How Is Boat Horsepower Calculated?

The relevance of horsepower, the measurement of 550 foot-pounds per second, didn’t stop with the Industrial Revolution. The measurement of horsepower was converted into other units of measurement. For example, other experiments determined one horsepower equals 746 watts of energy. In other words, if you put a one-horsepower horse on a treadmill, it would be able to operate a generator producing 746 watts. Engineers also did calculations to relate horsepower to torque, which is especially important for boat engines.

Torque is easiest to explain through an example. Imagine you have a large socket wrench with a two-foot handle. You apply 50 pounds of force to that handle — when you do that, you’re applying a torque or turning force of a total of 100 pound-feet to the bold. Keep in mind, with that calculation, you could get the same result — 100 pound-feet of torque — by applying one pound of force to a socket wrench with a 100-foot handle, or by applying 100 pounds of force to a socket wrench with a one-foot handle.

In an engine, torque produces power — so being able to relate it to horsepower is critical. A device called a dynamometer applies a load on the engine and then measures the amount of power it produces to determine torque. Marine dynamometers are available, too — taking into consideration boat operation by simulating on-the-water operation. Once the torque has been determined, you’re able to convert torque to horsepower by multiplying torque by revolutions per minute (rpm) and dividing that product by 5,252. The divisor, 5,252, comes from a series of calculations that convert rpm to radians per second.

Through using a dynamometer, you’ll be able to see the horsepower versus rpm values for the engine, which is especially important for calculating peak horsepower. Engines will have a point in rpm at which the power available from the engine has reached its maximum. This is known as peak horsepower — it’s often documented as “___ HP at ____ rpm.”

Determining How Much Horsepower You Need

Once you understand the history of horsepower and how that’s connected to the calculation we use today, it’s natural to wonder how much horsepower your boat needs. There are several factors to take into consideration when you’re determining how much horsepower you need — the manufacturer’s limits and recommendations, boat horsepower-to-weight ratio, fuel efficiency, use of the boat, number of people on the boat and an industry rule of thumb. Here are some things to consider in each of these areas to help you answer the question, “How much horsepower do I need for my boat?”

Manufacturer Limits

The easiest place to start is with the boat’s capacity plate — or owner’s manual. In addition to giving you a maximum for passengers and cargo, the manufacturer will also spell out the absolute maximum boat horsepower. If you have a boat that was built before 1972, came from overseas or was home-built, you may not have a capacity plate, but boat owner’s manuals are often available online. If not, you can always contact the boat’s manufacturer to inquire about their limits and recommendations for your particular boat model .

Boat Horsepower-to-Weight Ratio

When you’re trying to determine the amount of horsepower you need, it’s essential to consider the weight of the boat. The boat horsepower-to-weight ratio is simple to calculate and can be expressed in horsepower per pound or pounds per horsepower.

Let’s say, for example, your boat weighs 5,000 pounds, and it has a 300-horsepower engine. Taking 5,000 divided by 300 gives you a result of 16.6 pounds per horsepower. Doing the opposite calculation — taking 300 divided by 5,000 — gives you a result of 0.06 horsepower per pound. The lower the number, the faster your boat will go. Remember the boat horsepower-to-weight ratio once you’ve decided on horsepower and are matching outboard to boat size. While one or two outboards may give you the same horsepower result, keep in mind additional weight will accompany each additional outboard motor.

Fuel Efficiency

The amount of horsepower you choose will impact your fuel efficiency. However, just because you have a higher-horsepower engine does not necessarily mean you’re going to use more fuel. According to  Boating  magazine , running your gas engine between 3,000 and 3,500 rpm and your diesel engine at three-quarters throttle is the sweet spot for fuel efficiency. If you’re running a lower horsepower engine at full throttle all the time, it’s going to use more gas than a higher horsepower with less throttle. Keep this fact in mind as you consider what horsepower to choose.

For those who prefer exact calculations,  Boating  magazine  has provided some calculations you can use to run some of the numbers. You’ll be calculating the gallons of fuel that are burned per hour (GPH). To do this, you need to know gasoline weighs approximately 6.1 pounds per gallon, while diesel weighs about 7.2 pounds per gallon. You also need to know a well maintained four-stroke gasoline engine is estimated to burn about 0.5 pounds of fuel per horsepower per hour, while a similar diesel engine is estimated to burn 0.4 pounds of fuel per hour.

The equation is GPH = (specific fuel consumption x HP)/fuel specific weight. For example, if you want to determine the fuel consumption for a 300-horsepower gasoline engine, you would calculate (0.50 x 300)/ 6.1, giving you a result of 24.5 gallons per hour.

As with most decisions related to boating, the use of the boat is always a factor. Are you using the boat just to cruise with friends and family ? Or will you be pulling water skiers, wakeboarders and tubers ? The addition of pulling someone behind the boat — and the additional weight of storing watersport accessories — increase the need for power and are often a reason to consider adding horsepower to your boat.

Number of People

Once you’ve considered the use of your boat, the next question to ask is what the normal number of passengers for your boat will be. If it’s usually just you and a friend or a spouse, that weight is different than if you enjoy boating with several of your family members and friends.

Rule of Thumb

If you’re the type of person who doesn’t need precise calculations — or just doesn’t want to be bothered with them — the  Boat Trader  blog offers a rule of thumb to use when determining the amount of horsepower for your boat. The rule of thumb is based on weight alone, and says you should have between 40 and 25 pounds of weight for each horsepower.

For example, a 5,000-pound boat could have an engine with between 125 and 200 horsepower. Yes, the range is wide, but that’s because boats have a variety of different designs and handle differently. While this rule of thumb can be a helpful way to get a ballpark range, it still requires some guesswork when it comes to considering your boat handling.

Federal Regulations

Is it illegal to overpower a boat? According to the federal government, yes. There are a few different ways you can define overpowering a boat. The horsepower capacity section of the  Code of Federal Regulations  contains its definition of overpowering a boat.

There are two different ways the federal government uses to determine the maximum horsepower for any given boat — one is a computation, and the other is a performance test. The way that is used depends on the boat. For the majority, the computation method is best to use. You multiply your boat length by the transom width. Then you take that number, which is known as the “factor,” and  match it to a horsepower capacity according to the Code of Federal Regulations Table 183.53  — Outboard Boat Horsepower Capacity, shown below.

Don’t forget to adjust the result based on remote steering, transom height and boat bottom.

The performance test method is for boats that are 13 feet or less in length, have remote wheel steering, have a maximum capacity of no more than two persons and at least a 19-inch transom height — or at least a 19-inch motorwell height and at least a 15-inch transom height. Through this method, there are very specific instructions for boat preparation addressing everything from motor mounting to fuel tanks to ensure consistency. There are equally as specific instructions for the conditions in which you can perform this test.

The first part of the performance test is the quick-turn test. Setting the throttle at a low maneuvering speed and facing straight ahead, you then turn the wheel 180 degrees in half a second or less and hold it there. If you can complete the 90-degree turn without losing control of the boat or reducing the throttle, your boat has passed the test. Repeat, increasing the turn in speed until you can no longer pass the test, or you reach the maximum throttle. The maximum horsepower the boat can use while still completing this test is defined as the maximum horsepower capacity, unless it is more than 40 horsepower, in which case, the maximum horsepower capacity is capped at 40.

The good news is, these rules are in place for boat manufacturers, so assuming your boat’s manufacturer is following the federal regulations, you can consider the maximum horsepower capacity listed on your boat meets the federal regulation for its maximum horsepower.

Insurance Considerations

The amount of horsepower your boat has will influence your boat insurance, which is another fact to consider. There are three main areas of insurance the amount of horsepower you choose for your boat will affect — overall coverage, premium cost and type of policy.

Overall Coverage

There is also a chance your insurance company will not cover a vessel that exceeds the boat manufacturer’s max horsepower. This is an extremely important factor, as it could affect your ability to get insurance coverage for your boat. If your boat is currently insured and you’re considering a motor upgrade, make sure you know your insurance company’s rules for horsepower limits. If you upgrade without abiding by these rules and notifying your insurance company, there’s a good chance they won’t cover any claim you file.

Premium Cost

While abiding by your insurance company’s rules for boat horsepower, it’s important to remember that doesn’t mean a change in horsepower won’t bring a change in your premium cost. As a rule of thumb, boats with higher horsepower will be more expensive to cover.

Type of Policy

In addition to solely considering the horsepower of the boat, the overall size of the vessel, which takes horsepower into account, may determine the type of boat insurance policy you need to get. For example, your homeowner’s or renter’s insurance policy will usually cover smaller powerboats with less than 25 horsepower. Boats that are larger and have more than 25 miles per hour horsepower almost always require a separate boat insurance policy.

Dangers of Overpowering Your Boat

Bigger and faster is not always better. Putting more horsepower behind your boat may seem like an innocent way to add some excitement to your boating experience, but it could cost you a significant amount of money in fines, lawsuits and damage to your boat. Here are a few examples of how your need for speed can get you in trouble when it comes to boat maximum horsepower.

Breaking the Law

Is it illegal to overpower a boat? In some cases, yes. There are federal laws in place to ensure the appropriate horsepower limits are listed on all boats. State and local laws regarding overpowering your boat vary. Make sure you know the state and local laws for the areas in which you’ll be boating. Otherwise, your excess horsepower may be putting you at risk for fines and other consequences.

Accident Lawsuits

Even if your state and local laws don’t address overpowering your boat, you’re still putting yourself at risk in other ways. If you’re in an accident, the fact that your boat’s horsepower is above and beyond the manufacturer’s recommendations will be in the accident report. While you may not have fines because of breaking state and local laws, you are very susceptible to being found negligent and the victim of a lawsuit, especially in a case where there are damages.

Too Much Weight

In recent years, more horsepower hasn’t always meant more weight. However, it is still true in some cases, and that additional weight is another component of high horsepower that can be dangerous. For example, the additional weight can make a self-draining cockpit useless, leading to flooding problems.

Boat Damage

Even with additional horsepower that doesn’t add weight to the boat, the additional speed applies pressure that can cause significant damage to your boat. Every part of your boat, from the transom to the bow, was created to withstand a certain amount of pressure and stress. If you decide to ignore the boat’s maximum horsepower and overpower it, you’re exposing every part of your boat to pressure above and beyond what it was designed to endure, risking significant damage to the hull of your boat.

Finding a Boat With the Ideal Balance

As a boat manufacturer, at Formula Boats we know the balance of giving you the power and speed you want while making sure safety is a priority. If you’re considering purchasing a boat, our online  boat builder  gives you the opportunity to fully customize several different boat models with a few different horsepower options. You can be sure horsepower options for each boat model we provide are within the limits we believe maximize your performance while maintaining safety.

Discover a boat you like through our boat builder? We have dealers located throughout the country ready to help you find your boat. Get started by  searching for the dealer  location closest to you on our website.

Even though we narrow down the options, it can still be tough to choose the amount of horsepower that will give you performance based on boat weight and use, but also fuel efficiency. If you’re interested in one of our boat models, but are still wondering how much horsepower you need, we’re here to help — please don’t hesitate to  contact us .

Contact Dealer

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply

• Sailboat Maintenance Tips
• Eco-Friendly Sailing Practices
• Sailboat Buying Guide
• Sailboat Insurance and Finance
• Sailboat Safety and Regulations
• Sailboat Technology Advances
• Sailing Gear and Equipment
• Sailboat Navigation Essentials
• Sailboat Restoration Projects
• Sailboat Interior Design
• Sailing Destinations Worldwide
• Sailboat Types and Designs

The Essential Guide to Outboard Motors on Sailboats

outboard on sailboat specs

In the world of sailing, having a reliable outboard motor for your sailboat can greatly enhance your overall experience on the water. Whether you’re cruising along quiet coastlines or navigating tricky docking maneuvers, the right outboard can make all the difference. Here, we will explore the essential specifications you should consider when choosing an outboard motor for your sailboat.

Power is a crucial factor when it comes to outboard motors on sailboats. The horsepower rating determines the speed and maneuverability of your sailboat, so it’s important to select the appropriate power based on your needs. Consider factors such as the boat’s size and weight, typical wind conditions, and intended use. Additionally, opt for motors that feature a reliable start mechanism like an electric starter. This will ensure convenience and ease when igniting the engine.

outboard on sailboat review

When it comes to choosing the right outboard motor for your sailboat, there are several factors to consider. From power and reliability to efficiency and quietness, finding the perfect match can greatly enhance your sailing experience. In this review, we will delve into the world of outboard motors and explore the key features and benefits that are essential for any sailor.

1. Power and Performance:

• Look for outboard motors that provide sufficient power to navigate through different weather conditions and water currents.
• Consider the motor’s horsepower, as it determines the speed and maneuverability of your sailboat.
• Opt for a motor that has good torque, allowing it to efficiently move your sailboat even against strong winds.

2. Fuel Efficiency and Range:

• Choose an outboard motor that offers excellent fuel efficiency , allowing you to sail longer distances without running out of fuel.
• Consider the motor’s fuel capacity to ensure it fits your sailing needs and allows for extended voyages.
• Look for features such as fuel-injection systems or advanced technology that optimize fuel consumption.

outboard on sailboat pros and cons

• Flexibility: One key advantage of having an outboard motor on a sailboat is the flexibility it provides. Unlike fixed inboard engines, an outboard motor can be easily removed or angled, allowing for improved maneuverability in tight spaces and shallow waters.
• Cost-effective: Outboard motors are generally more affordable than inboard engines, making them an attractive option for sailors on a budget. Additionally, they require less maintenance and are easier to repair.
• Weight distribution: Placing the outboard motor on the transom allows for optimal weight distribution, which can have a positive impact on the boat’s stability and performance.
• Noise and vibration: Outboard motors tend to generate more noise and vibration compared to inboard engines. This can be a disadvantage for those seeking a quiet and smooth sailing experience.
• Weather exposure: Since outboard motors are located on the transom, they are more exposed to the elements, including saltwater corrosion. Regular maintenance, such as flushing with freshwater and appropriate protection, is crucial to ensure longevity.
• Less power: In comparison to larger inboard engines, outboard motors typically provide less power. This may impact the boat’s speed and ability to handle adverse weather conditions .

outboard on sailboat interior photos

Are you curious to see how outboard motors are integrated into the interior of sailboats? We’ve got you covered with a collection of stunning photos that showcase the unique design and functionality of these watercraft beauties. From sleek and compact installations to innovative space-saving solutions, these images capture the creativity and versatility of outboard motor placements in sailboat interiors.

Explore the photo gallery below to get inspiration for your own sailboat interior design. Witness how these outboard motors seamlessly blend with the overall aesthetic of the boat, while providing efficient propulsion and maximizing interior space. Whether you’re a seasoned sailor or an aspiring boat owner, these pictures will surely spark your imagination and offer a fresh perspective on the endless possibilities that outboard motors bring to sailboat interiors.

outboard on sailboat specifications

Choosing the right outboard motor for your sailboat is crucial for optimizing performance and ensuring a smooth sailing experience. Consider these key specifications when selecting an outboard motor that meets your specific needs:

1. Power Output:

• Look for a motor with sufficient power to propel your sailboat efficiently, considering its weight and size.
• Consider the maximum and cruising speed you desire, and select an outboard motor with an appropriate power output to achieve your desired performance.

2. Shaft Length:

• Determining the right shaft length is essential to ensure that the propeller is adequately immersed in the water.
• Measure the distance from your boat’s transom to the waterline, and select an outboard motor with a shaft length suitable for your boat’s setup.

3. Fuel Efficiency:

• Consider the outboard motor’s fuel consumption rate to ensure cost-effectiveness and longer cruising range.
• Look for motors with features such as fuel injection and advanced propeller design that enhance fuel efficiency.

outboard on sailboat layout

When it comes to sailboat design and layout, the placement and configuration of the outboard motor play a crucial role. A well-thought-out positioning ensures optimal performance and convenience for sailors. One popular layout option is to mount the outboard motor on a stern bracket, which is a sturdy metal bracket attached to the transom. This placement offers several advantages, such as easy access for maintenance and improved maneuverability while docking.

Another layout option involves installing an outboard motor within a well in the cockpit. This design keeps the motor protected and gives the boat a sleek appearance. Additionally, this setup maximizes cockpit space and allows for smooth movement throughout the boat. Sailors who prefer tiller steering often choose this layout, as it provides direct control over the motor and helps maintain balance while navigating challenging conditions. Whichever layout is chosen, it is important to ensure proper ventilation for the motor to prevent overheating and maintain its longevity.

The Essential Guide to Outboard Motors on Sailboats features

outboard on sailboat data

When it comes to sailboats, having an outboard motor can greatly enhance your sailing experience. Whether you need a reliable backup power source or simply want to maneuver more easily in and out of marinas, an outboard motor is an essential piece of equipment. Let’s explore some important data about outboards on sailboats and the valuable benefits they offer.

Improved Maneuverability:

• An outboard motor provides greater control and maneuverability, especially in tight spaces or when navigating in tricky conditions.
• With adjustable thrust and instant response, you can easily steer and change direction without relying solely on the wind.
• Outboards are usually designed to tilt, allowing you to raise and lower the motor as needed, ensuring maximum efficiency and performance.

Peace of Mind and Safety:

• An outboard motor serves as an additional power source, enabling you to confidently sail even when the wind isn’t in your favor.
• In case of any unexpected emergencies or equipment failures, having an outboard can be a lifesaver, providing the necessary backup to reach safety swiftly.
• Outboards are typically lightweight and can be easily serviced or replaced, ensuring minimal downtime and increased reliability.

outboard on sailboat diagram

The outboard on a sailboat diagram illustrates the key components and functionality of this vital piece of equipment. This diagram provides an excellent visual representation of how the outboard motor is integrated into the sailboat’s design and how it powers the vessel in various conditions. Understanding this diagram is essential for any sailor, whether you are a seasoned sailor or a novice looking to embark on your first sailing adventure.

In the diagram, you will notice the following components:

• Outboard Motor: The main engine that provides thrust for the sailboat.
• Mounting Bracket: The apparatus that securely holds the outboard motor to the boat’s transom.
• Propeller: The rotating blades that propel the sailboat forward or reverse.
• Throttle: The control lever that allows the sailor to increase or decrease the engine’s power.
• Steering Mechanism: The system that enables the sailor to steer the sailboat by turning the outboard motor.

outboard on sailboat for sale

Looking for the perfect outboard motor to power up your sailboat and enhance your boating experience? Look no further!

If you’re in the market for an exceptional outboard motor for your sailboat, we have a fantastic selection available. Our high-quality motors are designed to provide reliable performance and ensure smooth sailing on any adventure. Whether you’re a seasoned sailor or a beginner, having a reliable outboard motor is crucial for maneuverability, safety, and peace of mind.

Why choose our outboard motors?

• Powerful and efficient: Our range of outboard motors are built to deliver the power you need, allowing you to effortlessly navigate through diverse water conditions.
• Durable and long-lasting: Crafted with precision engineering and quality materials, our outboard motors are designed to withstand the test of time, giving you years of worry-free performance.
• Versatile and easy to use: Our motors are suitable for a variety of sailboats, ensuring a seamless integration with your vessel. They are also straightforward to install and operate, making them ideal for both novice and experienced sailors.
• Low maintenance: We understand the importance of hassle-free boating. Our outboard motors are designed with user convenience in mind, requiring minimal maintenance while delivering maximum reliability.

Q: What is an outboard motor and why is it essential for sailboats? A: An outboard motor is a portable propulsion system mounted on the back of a sailing vessel. It serves as the main source of propulsion for sailboats, allowing them to maneuver more easily in calm or adverse conditions, and serves as a backup power system if wind conditions are not favorable.

Q: What are the advantages of using an outboard motor on a sailboat? A: Outboard motors offer several advantages for sailboats. Firstly, they provide reliable and efficient power when needed, ensuring the ability to maneuver in tight spaces or navigate against strong currents. Additionally, they serve as a safety measure during emergencies or in situations where sails alone may not be sufficient. Outboard motors are also portable, allowing for easy removal and storage, which enhances the overall convenience for boat owners.

Q: Are there different types of outboard motors available for sailboats? A: Yes, there are various types of outboard motors available on the market. Sailors can choose from two-stroke or four-stroke engines, each with its advantages. Two-stroke engines tend to be lighter, more compact, and offer higher power-to-weight ratios, making them popular for smaller sailboats. Four-stroke engines, on the other hand, are generally more fuel-efficient and environmentally friendly, producing less noise and emissions.

Q: How do I properly maintain and care for an outboard motor on a sailboat? A: Regular maintenance is important to ensure the longevity and smooth functioning of an outboard motor. Changing the engine oil, checking and replacing filters, inspecting spark plugs, and lubricating moving parts are all important aspects of maintenance. Flushing the motor with freshwater after usage in saltwater is also crucial for preventing corrosion. Additionally, following the manufacturer’s guidelines and having the motor professionally serviced periodically are advised.

Q: What safety precautions should be taken when using an outboard motor on a sailboat? A: Safety should always be a priority when using an outboard motor on a sailboat. It is essential to read and understand the manufacturer’s safety guidelines before operation. Wearing personal flotation devices (PFDs) is strongly recommended for everyone onboard. Additionally, maintaining a proper distance from swimmers or divers, avoiding loose clothing that can get entangled in the motor, and ensuring the motor is properly secured and not running in enclosed spaces are all crucial safety measures to observe.

Q: Can an outboard motor be used while sailing? A: While it is not recommended to use an outboard motor while actively sailing, it can be used as an auxiliary power source when necessary, such as when entering or exiting a harbor, navigating narrow channels, or when winds are insufficient. However, it is generally preferred to rely on sails alone to maintain a more efficient and environmentally friendly sailing experience.

Q: What factors should be considered when choosing an outboard motor for a sailboat? A: Several factors should be taken into account when selecting an outboard motor for a sailboat. These include the size and weight of the sailboat, the intended usage, the required power output, the motor’s fuel efficiency, noise levels, and the overall budget. Assessing these variables will help determine the most suitable outboard motor for a sailboat, ensuring optimal performance and satisfaction.

Q: Are there any legal requirements or regulations associated with using an outboard motor on a sailboat? A: The use of outboard motors on sailboats may be subject to specific regulations and legal requirements depending on the jurisdiction and the size of the motor. It is crucial to consult local maritime authorities or boating authorities to ensure compliance with any licensing, registration, or safety regulations that may apply. Familiarizing oneself with the particular laws and regulations in their sailing area will help ensure a safe and enjoyable experience.

The Way Forward

In conclusion, understanding the essential guide to outboard motors on sailboats is crucial for any sailing enthusiast. As we have explored in this article, outboard motors play a vital role in enhancing the overall sailing experience, providing increased maneuverability, convenience, and reliability to sailboat owners.

By choosing the right outboard motor based on size, type, and power output, sailors can ensure optimum performance and efficiency. Regular maintenance and proper usage will prolong the lifespan of the motor and ensure its smooth operation. Furthermore, being aware of the various safety measures when handling outboard motors is pivotal to maintaining a safe and enjoyable sailing journey.

While outboard motors might seem complex at first, this comprehensive guide has aimed to simplify the knowledge surrounding them. By familiarizing yourself with the terminology, components, and maintenance requirements, you will be equipped with the necessary expertise to make informed decisions when it comes to selecting, using, and maintaining your outboard motor.

Whether you are a seasoned sailor looking to upgrade your outboard motor or a novice sailor exploring the options for your first sailboat, this guide has provided a solid foundation of knowledge to help you navigate the waters of outboard motors on sailboats.

Remember, each sailboat has unique needs and preferences, so take the time to research, consult professionals, and consider your specific requirements before making a purchase. With the right outboard motor onboard, you can embark on countless adventures, confidently embracing the joys of sailing the open seas.

• Recent Posts

• EVERGLADES BOATS V 2007 Boats for Sale & Yachts Updated for 2023 - March 19, 2024
• Carver 45′ Voyager 2003 Boats for Sale & Yachts Updated to 2023 - March 19, 2024
• Pacific Seacraft 1987 Boats for Sale & Yachts in 2023 - March 19, 2024

Related posts:

LEAVE A REPLY Cancel reply

Save my name, email, and website in this browser for the next time I comment.

EVERGLADES BOATS V 2007 Boats for Sale & Yachts Updated for 2023

Carver 45′ voyager 2003 boats for sale & yachts updated to 2023, pacific seacraft 1987 boats for sale & yachts in 2023, carver 45′ voyager 2000 boats for sale & yachts updated for 2023, silverton 45′ convertible 2007 boats for sale & yachts in 2023, more from author.

Quick Links

• Privacy Policy
• Cookie Policy

Popular Articles

• What's My Car Worth?
• Buyer's Guide

Yamaha's Got a New 7600-RPM, 200-HP Four-Cylinder Engine

We'll take our new engine debuts where we can get them these days. Even if they're in boats.

But the marine industry is a different story, and in recent years some of the coolest new engines— Mercury's V-12 , Honda's V-8 —were designed for boats. Which is also the case for Yamaha's new 1.9-liter four-cylinder, which makes 200 hp at 7600 rpm and can be found powering high-output WaveRunners and jet-drive boats. It's not designed for cars, but the Lemons racers among us can dare to dream.

The 1.9-liter four replaces Yamaha's 180-hp 1.8-liter mill and blurs the performance line between the company's naturally aspirated and supercharged engines. Yamaha's supercharged 1.8-liter makes 255 horsepower, but in a WaveRunner there's not a huge practical difference between the boosted 1.8 in a SVHO model and the naturally aspirated 1.9 that powers HOs. Personal-watercraft manufacturers adhere to an agreement that's something like the old German pact to limit top speeds to 155 mph, except on the water the target is 65 mph. That spec includes a 2-mph fudge factor, which naturally means that PWCs of sufficient horsepower top out at an electronically limited 67 mph. Since a 200-hp WaveRunner can hit that limit, the only difference is how quick you get there.

The 1.9-liter, as a new design, enjoys a bundle of changes aimed at durability and refinement. One example: There's an extra bolt connecting the cam chain housing to the block—a little tweak that makes a big difference. "The cam chain room is a thin aluminum casting," says Mark Sagers, senior watercraft factory service technical specialist (in other words, the guy who knows all the engines inside out). "That great big straight piece of aluminum is like a sound board, amplifying the noise of the cam chain. But if you run a fastener from that to the main casting, it knocks that noise way down. That's important when you're sitting right on top of the engine and it's bolted to a guitar body, basically."

Performance-enhancing upgrades include a new exhaust manifold with dedicated pipes for cylinders one and four, a bore increase from 86 mm to 88 mm, and a channel to route cooling water between the exhaust valves to cool the valve seats. The 1.9 even uses about a half-quart less oil than the 1.8, because Yamaha determined that it could cut windage losses (read: increase horsepower) without sacrificing durability. And durability versus performance is always a tradeoff, whether on land or not. "In a 250-cc motocross bike, the maintenance schedule calls for a new piston every nine hours and it's putting out specific power like a NASCAR engine, or almost Indy," says Sagers. "Boats are more on the lower end of high performance, so we can make them last thousands of hours."

A car engine might well make its horsepower peak beyond 7000 rpm, but it isn't expected to spend much time there. An engine destined for a WaveRunner is a different story. "A lot of the durability testing is done fully loaded at wide open throttle," Sagers says. "These will run a very long time at WOT. Waverunners are often idling or WOT, and there's no middle ground. But I've seen Waverunner engines with more than 1500 hours and no major mechanical work. It's staggering that these mechanical things can live through this."

Still, 200 hp isn't enough for everyone. Logically, it would seem inevitable that this engine will get a supercharger and the 1.8-liter will be retired. Boost prognosticators might find a clue at the 1.9-liter's Coast Guard–mandated intake flame arrester—the intake manifold is cast around it so it can't be sucked into the engine. Which is the kind of thing that would probably only happen if said intake was huffing some major boost. Perhaps soon, it will be.

In the meantime, you can break the 200-hp barrier without forced induction. And for twin-engine boats, that means Yamaha is packing 400 horsepower into some of its 22-footers, which we imagine would mean 50-plus-mph top speeds given that the 210 FSH hit 48.0 mph with the 1.8s and their 360 total horsepower.

Yamaha has built some nice automotive engines—most famously, the Ford Taurus SHO's —but those of us dreaming of 200-hp Yamaha-powered Miatas will probably have to wait a while for these latest ones to hit the salvage yards. (You can spend that interim figuring out how to adapt a closed-loop cooling system, since the jet drive on these engines doubles as a water pump.)

Calling a powerplant a "boat motor" is traditionally a pejorative, meaning a low-revving hunk of iron, an outdated castoff better suited as a mooring. But motors are electric, and that's where things are heading on the highways. So if you appreciate the mechanical complexity and cleverness of engines, boats are the new—and maybe last—frontier.

Ezra Dyer is a Car and Driver senior editor and columnist. He's now based in North Carolina but still remembers how to turn right. He owns a 2009 GEM e4 and once drove 206 mph. Those facts are mutually exclusive.

.css-190qir1:before{background-color:#000000;color:#fff;left:0;width:50%;border:0 solid transparent;bottom:48%;height:0.125rem;content:'';position:absolute;z-index:-10;} News .css-188buow:after{background-color:#000000;color:#fff;right:0;width:50%;border:0 solid transparent;bottom:48%;height:0.125rem;content:'';position:absolute;z-index:-10;}

Ford Planning $25,000 Compact EV for 2026: Report

New AMG GT43 Coupe Has 416-HP Turbo Four and RWD

The 2024 Hyundai Santa Fe's Most Notable Features

Hertz CEO Resigns after Buying 100,000 Teslas

2024 Hyundai Santa Fe Has Lots More Cargo Space

Fisker Pauses Production for Six Weeks

Rivian Models Can Now Use Tesla's Superchargers

2025 Q6 and SQ6 e-tron Advance Audi’s EV Game

Ford BlueCruise Is the Subject of a Federal Probe

2026 Mercedes-AMG EV Teased While Snow Testing

2024 Mercedes-AMG GT Starts at $136,050

• 2024 BOAT BUYERS GUIDE
• MIAMI BOAT SHOW
• Email Newsletters
• Fishing Boat Reviews
• Fly Fishing
• Marine Electronics
• Fishing Tackle
• Best Marine Electronics & Technology
• Fishing Destinations
• The Bahamas Fishing Guide
• Boating Safety

How Much Horsepower Does Your Boat Really Need?

• By Alan Jones
• September 4, 2023

This could be the shortest column in marine journalism history. “To determine how much horsepower to put on your boat’s transom, find the manufacturer’s maximum horsepower specification, and whatever number is listed there is the total power to install.” While that’s a good rule of thumb, there might be times when less is more. 

Go for the Max?

One good reason to get the most power possible lies in durability and longevity. The greater the horsepower, the less an engine has to work to keep the boat on plane with greater efficiency. Let’s look at an example. The Pathfinder 2005 TRS with a Yamaha F115 will have to operate at 5,500 rpm to reach 36.5 mph and will get 3.5 mpg. Power the same boat with an F150 and it reaches 35 mph at 4,500 rpm and will get 3.9 mpg, according to the manufacturer-­supplied performance data. This example also illustrates that the notion that less horsepower equals better fuel economy isn’t always true. Top speed is another reason to max out the ponies. More horsepower translates to a higher top speed. Sometimes the difference is dramatic. A Sundance FX19 flats boat with a Yamaha F90 will reach 41 mph, but it’s a 60 mph boat with an F150. Then there’s the resale value. If a buyer is looking at two identical boats and one has more power than the other, they will ­typically choose and often pay more for the more powerful boat.

Mo’ Power, Mo’ Money

Often, taking even a small leap in power can cost big bucks. The standard engine on the Blackfin 232DC is the Mercury 225XL FourStroke, but bumping it just 25 hp to the Mercury 250XL will cost $4,921 more. In this case, the big jump comes by moving from the 3.4L family of V-6 engines to a 4.6L V-8 for the 250. When reviewing the build-a-boat feature found on most manufacturers’ websites, compare the cost with different engines and look for the sweet spot where the least amount of money buys the biggest jump in ­horsepower. Often, the max-­power option is an exotic engine that comes with a larger-than-­proportional price tag. 

Read Next: How Much Fuel Capacity Do I Really Need?

Less Power Equals Less Weight?

Sometimes, adding more horsepower changes the weight drastically, but an increase in horsepower often adds no weight because it is done via programming the engine’s electronic control unit. For years, Mercury’s supercharged Verados all shared the same 2.6L inline-six-­cylinder block, even though the horsepower could range from 200 to 400, with a weight difference of just 38 pounds. 

In the case of the Mercury 225XL V-6 versus the 250XL V-8, the weight difference is 52 pounds, which might not seem like much but could be significant on a small flats boat. Using multiple engines just exacerbates the difference.

Moving to the largest engine can make a huge difference. Mercury’s new Verado 600 is a 7.6L V-12 behemoth with a host of technological advances, but it also weighs 1,260 pounds. Yamaha’s XTO Offshore 450 V-8 weighs 988 pounds. In comparison, the Mercury 450R weighs just 689 pounds. Although more weight can cause slower hole-shot times, often this is counterbalanced by the ­additional horsepower and the larger prop that a higher-horsepower engine can swing. Need an example? Take a look at the Mercury Verado 600 V-12 that turns a massive 18-inch-­diameter prop.  

Horsepower needs ­also change if only one or two people routinely use the boat. If you typically invite a crowd of friends to go fishing, powering up to the max might make more sense. Otherwise, the boat can be sluggish and slow to respond to the throttle.

Variables Matter

If a boat weighs more, it’s probably going to need more power, but factors such as the hull design also matter. A Carolina Skiff 21 SWS is a 21-footer that features a relatively flat hull bottom, weighs 2,351 pounds, and has a maximum horsepower rating of 150. The Regulator 23 has a steep 24-degree transom deadrise to help it slice through ocean waves and weighs 6,700 pounds with a single outboard. The smallest outboard you can buy it with has 300 hp.

If a boat has a transom deadrise of 20 degrees or greater and is run in waters that can get rough, err on the side of more power. During situations like running through a ripping inlet, having crisp throttle response is often needed to safely transit out or return.

If you’re not sure about how much power to choose, talking to a local dealer is a good idea. They have the experience with and information on the models they sell that can help you make the best possible decision when it comes to the question of, “How much horsepower do I really need?” 

• More: 2024 Boat Buyers Guide: More Resources , Boat Engines , Boats , October 2023 , outboard motors

Pursuit OS 405 Offshore

Prepare for Launch: The Springtime Vessel Safety Checklist

Honda Outboards and Scout Boats Create New Boat Line

World Cat 400CC-X

Where’s the Data for Making Changes to California’s Halibut Regulations?

Chasing Striped Bass Through New Jersey Marshes

Where to Find the Best Fishing in March

Kick Off Spring With the Southeast Mullet Run

• Digital Edition
• Customer Service
• Privacy Policy
• Cruising World
• Sailing World
• Salt Water Sportsman
• Sport Fishing
• Wakeboarding