choose your boat
making the right choice
choosing a sailing yacht
get the most from your yacht
monohull or multihull?
a cat or a tri?
cruising catamarans

making the right choice
Randy Harman

Right off the bat you need to know that there simply is no such thing as the best boat any more than there is the best car or the best food—only a compromise that fits your specific needs and budget. For those with infinite wealth, finding a suitable boat is a simple matter, but most of us on restricted budgets must prioritize. Your specific plans for cruising and the money you have available are the key ingredients that will dictate the relative importance of the features to consider. There are many good vessels out there that can serve your needs. Here are some of the important factors you'll need to keep in mind as you go about choosing one.

The perfect boat doesn't exist, says the author, so look for the one that best suits your needs and plans.

Cruising Plans    Numerous little decisions centre around the type of cruising you plan to do, and here many plans founder on the rocks of judgement error. Be honest with yourself at this stage—don’t be tempted to buy the all-weather, ‘round-the-world boat for short coastal cruises and island hops.

If your plan is to limit passages to coastal areas, fuel and water capacities are not the prime criteria. The same is true for storage space. But if long, offshore cruises loom on your horizon, consider the minimum factors of one gallon of water per person per day and sufficient fuel tankage for motoring 400 nautical miles. any cruisers even suggest adding a factor of 50 percent to these numbers, but sailing more minimizes fuel consumption, and the use of salt water for bathing, washing clothes, and doing dishes can help to reduce freshwater usage.

Ship’s stores require space, and the longer the voyage, the more you need to carry. Most blue-water cruisers stow at least a 30-day supply of staples aboard. You can start with a storage space figure of one cubic foot per day for a couple, but lifestyle variations can drastically alter that number. I have yet to see an offshore cruiser leave port with storage lockers that were only half full, but coastal cruisers often let the larder get rather bare. Be aware that all lockers eventually fill up, regardless of their size, and that storage is a cubic function—a 40-foot vessel will typically have a volume about 2.2 times that of one 30 feet long.


As sailors reach their late 50s and beyond, creature comforts become more important. The luxuries of our youth now seem more like necessities, and to accommodate these necessities, boat size tends to become more important. It is natural to consider the largest boat your budget will allow. But heavier ground tackle, larger sail areas, and greater maintenance costs have to be seriously considered along with the size.

Remember the stores you place aboard will influence your boat’s draft. During our years of full-time cruising we raised OuiSi’s waterline by six inches, and performance suffered as a result. Of course, larger boats are less vulnerable to effects of additional loading.

Sailing to remote and beautiful places requires a boat that's up to the job of getting you there safely and in an expeditious manner.

If you plan to follow the lead of migratory birds along the Intracoastal Waterway—heading south for the winter and north for the summer—a good engine is important. Weather windows are often capricious in spring and fall, while currents and scheduled bridge openings along the ICW can make for slow progress. In fact, I’ve never heard a coastal cruiser complain about having too much engine power, but know of many that wish they had more. On the other hand, a few offshore cruisers have no engine at all. Mast height is also crucial, as many inland routes are subject to overhead obstructions as low as 46 feet—certainly a boat with a stick more than 65 feet off the water cannot use the inland routes.


Geography    Where  you intend to cruise  should have a strong impact on what boat you select. For instance, in Panama, the tidal range is up to 15 feet on the Pacific side and six inches on the Caribbean side. Tidal ranges in the Pacific Northwest and Northeastern Atlantic dictate the need for a power plant capable of overcoming four to six-knot currents, but this is unnecessary in the Caribbean.

If the scene above was your intended cruising ground, you probably would want a boat that with a pilot house, as well as a few other amenities. 

Deep-draft sailboats are common along the Pacific coast, and before transiting the Panama Canal, I thought any water depth less than 30 feet was shoal. We now go for miles in the Bahamas with less than two feet beneath our keel. It might be easy to conclude that a shoal-draft boat is more desirable, but most offshore cruisers prefer deeper draft to reduce leeway and enhance stability. This just reinforces the initial premise that it is the cruising plans that should dictate the features you seek. If the plan is to undertake long, offshore passages and later gunkhole the shallow areas in some faraway place, a dilemma requiring some compromise will be in order.

Prevailing wind direction and strength also influence decisions over the vessel’s sailing capability. The common coastal cruiser’s lament is, “The wind always blows from the place we want to go!” So these folks would be better off with lightweight boats that are good at upwind work. Most circumnavigations, however, are made westward with trade winds abaft the beam. In this situation, a close-winded sailboat is less important than having a vessel that tracks and rides well in following or quartering seas.

Physical Abilities    The painful truth is that strength and agility diminish as we age. Physical exercise can reduce the rate of change, but it can’t totally stop the aging process. The senior sailor is less willing or able to transport fuel or water by jerry jugs, so tankage has greater importance as we get older. Each year I find it harder to use the boarding ladder; so maybe there is something to say for the “sugar-scoop” sterns of more contemporary designs. The more forethought you expend now on factors such as these, the more pleasant your retirement cruising will be.

We also look for seakindly vessels with a gentle motion and more stability so that they heel less. Numerous articles can be found on these subjects, but the final, best criterion is how the vessel’s motion feels to you.

The size of the boat, both length and displacement, has a direct relationship with the size of sails, anchors, and other parts. Maintenance chores such as bottom painting are three times as big on a 40 footer as on one that's 30 feet long. You might surmise, then, that just when we need the extra space and comfort of a larger boat, we no longer have the strength to sail her. The good news is that there are systems that help—like larger davits, winches, and windlasses that can do the heavy lifting. Having all lines lead to the cockpit can be very appealing after you’ve been to the mast a few dozen times to reef the main in the dark. Many prudent sailors cruising offshore throw in a reef at sundown so that the person off-watch can rest, and we have a rule aboard Oui Si that both of us must be topside if there is a need to leave the cockpit after dark. And other items like watermakers can help by making hand-carrying jerry jugs of water obsolete.

Some maintenance jobs also require strength. While the split rig of a ketch or yawl reduces the size of each sail and thus eases the effort of sail handling, that second mast means there is more hardware to maintain and replace. Over the years, I have become envious of those sailors who own vessels with unstayed spars. At 55, I thought nothing about using mast steps to go up the mast six or eight times in one day; now two or three is all I can handle, and even then my muscles complain the following day. So keep all of this in perspective as you go about your search.

A split rig might seem like a good idea to make sail handling more manageable, but it can almost double the maintenance of gear.

The Analytical Approach

Even with all the comparative data available, most people still choose a specific boat based on economics and aesthetics. The design of a sailboat is an elegant combination of science and art—and no understanding of this can truly reduce the topic to simple equations or ratios. However, there some formulas available that can help guide and temper our expectations regarding a new boat. If your compromises are well thought out, that could mark the beginning of a long-term love affair for all three involved—you, your significant other, and your boat.

The following formulas give valuable clues to the relative motion and performance of different sailboats. They allow you to compare the designs of various cruisers of different sizes. Note that the determining factor in most of the calculations is displacement, not length (and especially not length over all, or LOA). A long, light boat and a short, heavy one might have the same amount of sail area and ballast, but they could have very different motions and speed potentials.

  • The length-to-beam ratio (LOA divided by maximum beam) indicates interior storage space and nominal stability. An L/B value of 2.8 to 3.2. is common for smaller vessels and normally increases to between 3.6 and 4.0 for those in excess of 40 feet. A ratio higher than these numbers may mean an excessively narrow boat, while a lower ratio may prove to be too beamy to sail well.


  • The speed-length ratio is used for traditional speed estimates of displacement hulls. It is a constant multiplied by the square root of the waterline length (LWL). The constant most normally used is 1.34; thus a cruiser with an LWL of 36 feet would have a theoretical hull speed of 8.04 knots (square root of 36 = 6, times 1.34 = 8.04). Modern cruisers may exceed an S/L ratio of 1.4 on a beam reach, but on a long-term offshore cruise, the constant is probably closer to a value of 1.0. It is helpful to remember that the power needed to exceed hull speed is enormous relative to that used to drive the boat at or below hull speed.


  • Displacement-to-length is a non-dimensional ratio that allows comparison of displacement boats having different LWLs. The displacement is stated in long tons of 2,240 pounds per ton, and this is divided by 0.01 LWL cubed. Values of 280 to 320 are typical for cruisers. Boats with lower D/L ratio accelerate faster, even to the point of planing, but they may have an unacceptable motion in a seaway and have reduced carrying capacity.


  • The sail area-to-displacement ratio (SA/Disp 2/3)is perhaps the most important, but also the hardest to derive without a scientific calculator. The boat's sail area in square feet at 100 percent of the foretriangle is divided by the displacement stated in cubic feet of seawater (displacement in pounds divided by 64) to the 2/3 power, that is, first squared, then taken to the cube root. The SA/Disp 2/3 can be considered like the horsepower per pound of a motorboat. Higher ratios indicate better potential performance, but also increasing the need to reef as winds build. Most single hull cruisers have a ratio of between 14 and 18.