Average Sailboat LOA (Length Overall)
The average sailboat LOA is about 30 feet, depending on the type of sailboat. Racing sailboats of the same displacement tend to be longer and narrower, while bluewater cruising sailboats tend to be shorter and wider.
LOA, or length overall, is a measurement of the sailboat between its longest hull points. This is usually the measurement associated with the simple term ‘length.’ For example, an Islander 32 has an LOA of 32 feet, and a Cal 20 has an LOA of 20 feet. This is also the measurement used when referring to a vessel as a “30-foot sailboat” and whatnot.
Typically, LOA does not include the length of hull additions such as bowsprits and rigging. Also, it doesn’t consider any modifications such as outboard motors and fishing equipment.
As far as performance is concerned, LOA is actually not the most important measurement. Calculations such as hull speed and displacement, which are critical marine specifications, are made using LWL or length at the waterline.
Average Sailboat LWL (Waterline Length)
Waterline length is measured from the longest points of the submerged portion of the hull. This measurement is usually about 15% to 20% shorter than the LOA, as most sailboats have a sloped bow and stern that gets larger the further up the hull you go.
However, this is not always the case. Vessels with a ‘ram bow’ or reverse-sloped stern could have a waterline length that’s actually longer than the LOA. However, these unusual design elements are not common on popular production sailboats.
Average Catamaran Length
Catamarans, foot-for-foot, are actually much larger than monohulls. These vessels have two separate hulls, which themselves are nearly large enough to be separate sailboats. As a result, the average size of a comparable catamaran is often smaller, but large catamarans remain popular.
The average length of a production catamaran is about 40 to 50 feet overall. The LOA to LWL ratio of most catamarans is much less significant than monohulls, as the effects of hydrodynamics on catamarans are very different. For example, a 30-foot monohull probably has a 25-foot LWL, whereas a 30-foot catamaran could also have a 30-foot LWL.
Average Trimaran Length
Common production trimarans and catamarans both have a typical LOA of about 40 to 50 feet, though some popular 30 to 35-foot models exist. The LOA and LWL ratio differences between trimarans and catamarans are minimal, though many Trimarans have a much more substantial center hull.
Multi-Hull Waterline Length Variations
Multi-hull sailboats are designed to take advantage of the hydrodynamic lift effect. This phenomenon lifts the hulls of the vessel out of the water as they increase in speed, thus reducing drag and increasing speed and efficiency. The faster the multi-hull goes, the easier it is to gain even more speed.
Depending on the shape of the hulls, multi-hull sailboats can have a dynamically changing LWL in practice. That said, multi-hull LWL specifications are fixed at their non-moving point.
How Sailboat Length Impacts Speed
Sailboat speed and length are closely related. However, the relationship only has a significant impact on the waterline length of monohull designs.
Sailboat length/speed ratios are calculated as hull speed. For monohull designs, the hull speed calculation is (HS = 1.34 x √LWL). This determines the typical maximum speed of a boat based on its waterline length.
But why are sailboat speeds capped due to length? It has to do with wake. When a displacement hull moves through the water, it generates waves at the bow and the stern. These waves cause drag—which the vessel can overcome until a certain speed is reached.
At hull speed, the bow and stern waves ‘sync’ and begin working together against the boat. Once this harmonic interference begins, the effect increases and counteracts any additional wind power that the sails supply.
If you’ve ever seen a sailboat hull speed table, it’s evident that longer vessels can achieve higher speeds. This rule is a great way to measure the peak performance of monohulls by length, but it’s almost useless for multi-hulls.
Multi-hull Length to Speed Ratios
Multi-hull sailboats generate completely different kinds of hull waves, so the hull speed formula used for monohulls doesn’t do much good. This is why multi-hull sailboats of the same length can almost always outrun monohulls-even if they displace twice as much.
Why Are Some Sailboats Faster Than Their Hull Speed?
Modern hull designs don’t always conform to traditional hydrodynamic standards. The hull speed calculation was developed as a general tool for classical sailboat designs with full-displacement hulls.
One way to beat hull speed limitations is planing, but sailboats usually can’t achieve full plane. Modern materials have allowed designers to create sailboats with shorter lengths that exceed their hull speed. This is why hull shape is such an important factor when choosing a design.
The types of monohull sailboats that ‘beat’ their hull speed limitations are semi-displacement hulls, canoe hulls, and other hull types with a shallow draft (excluding a long and thin fin keel, bulb keel, or bilge keels).
Average Sailboat Length by Type
Here, we’ll provide a quick breakdown of average sailboat lengths by type. The smallest class of sailboats, called dinghies, rarely exceed 12 or 15 feet in length.
Other small sailboats, such as single-person racers, typically range in size from 12 feet to 18 feet. Examples include famous racers like the Sunfish and the Laser.
Average Small Sailboat Length
Small open-top displacement vessels, which were once common for fishing and used as workboats, range in length from 15 feet to 25 feet. Open-top sailboats with keels or centerboards rarely exceed 25 feet in length as there’s simply too much usable space to avoid installing a cabin.
Average Trailerable Sailboat Length
Trailerable sailboats, displacement-keel or otherwise, range in length from 15 feet to 26 feet. Sure, you may see a 28 or 30-foot sailboat on a large trailer, but that doesn’t make it a ‘trailerable’ design.
Trailerable sailboats are designed to be transported practically using normal cars, so their length and overall size are limited.
Average Coastal Cruising Sailboat Length
Small cruising sailboats range in size from 20 feet to 29 feet. These vessels are minimally capable of coastal cruising. That said, this is the size range where the smallest practical offshore cruising vessels live.
Famous compact blue water cruisers like the Flicka 20, Amigo 22, and the Dana 24 are capable and fall well within the coastal cruiser length category.
Average Cruising Sailboat Length
The sweet spot of common fiberglass production cruisers is between 30 and 40 feet, with the majority ranging from 30 feet to 35 feet. These are the most common sailboats of their type, as they usually offer the most capability and comfort for the most reasonable price.
These 30 to 35-foot cruisers are usually offshore-capable and small enough for local cruising. Plus, their cabins are large enough for a liveaboard couple or a vacation with friends and family.
Average Bluewater Cruising Sailboat Length
Serious Bluewater cruisers are designed for safe, fast, and comfortable ocean passages. These vessels range from 35 to 45 feet in length, and the majority are over 40 feet long.
Several well-known Bluewater cruisers range between 38 and 40 feet. These are spacious and comfortable vessels with fast hull speeds and acceptable handling characteristics.
