What is Sailboat Draft?
Draft is a term we use to describe how deep below the water a sailboat hull (and everything attached to it) goes. This information is useful because it gives us an idea of how the vessel handles and what conditions it can sail in.
For example, a 40-foot sailboat with a draft of 5 feet could make an excellent blue water passagemaker, but its draft is far too deep for beaching on an island or exploring shallow coral reefs.
Average Draft of Small Sailboats
Some small sailboats, known as island-hoppers or 'gunkholers,' are designed to have flat bottoms and. a retractable centerboard to reduce draft.
These vessels, which are designed to be beached and to sail in shallow water, have a board-down draft of a foot or two and a board-up draft of 10 inches or less. Smaller sailboats, such as dinghies, have an even shallower draft of Just a few inches.
Average draft of Coastal Cruising Sailboats
Coastal cruising sailboats are small, but they're a bit heftier than centerboard island hoppers. They range in size from about 22 to 30 feet in length, and they have an average draft of three feet.
Draft depth is reduced on some vessels that utilize swing keels, which are like centerboards that pivot up into a shallow trunk when the captain needs to reduce draft.
Average Draft of an Offshore Sailboat
Offshore sailboats are known for having a deep draft, and many of these boats keep a significant amount of ballast as low as possible to increase stability. The draft of offshore sailboats ranges from about 3.5 feet on the low end and 6 feet or more on the largest vessels.
Owners of offshore sailboats with deep drafts have to be very careful when navigating harbors and channels, as underwater obstacles or the seafloor can easily cause tremendous damage to a deep keel.
What is Shoal Draft?
A shoal draft sailboat is a vessel with a shallow draft, usually under 3 feet. Examples of shoal draft vessels include the Catalina 22 (with a swing keel) and the West Wight Potter 19. Shoal draft sailboats are usually flat-bottomed (like sharpie sailboats) or, more recently, built with V-bottom hulls.
Shoal draft vessels are great for rivers, lakes, and island hopping but usually aren't comfortable in heavy seas.
Does Draft Affect Stability?
Draft depth can affect stability, but it doesn't always. Instead, the things that affect stability often affect the draft of a sailboat. For example, a heavy ballast keel is long and deep, which helps a sailboat remain stable in rough weather.
A shallower boat with additional internal ballast will sit lower in the water, thus increasing its draft and stability. However, adding an extra two feet to a centerboard likely won't help increase stability, though it will dramatically increase your draft.
Draft Vs. Drag
Many people believe that deeper draft sailboats have more issues with drag than shallow draft boats. This is sometimes the case, but it doesn't tell the full story. Modern deep-draft sailboats often have shallow, rounded hulls and a long fin keel.
The fin keel, which is responsible for the vast majority of the draft depth, is narrow and designed to produce very little drag. These boats are fast and nimble, which makes them popular with modern sailors.
Older vessels with traditional full keels do experience more drag, though they enjoy enhanced stability and superior motion comfort.
Are Deep Draft Sailboats Better?
Deep draft sailboats are usually better for offshore sailing, and some modern deep draft vessels are great for racing. However, the majority of production racing sailboats have flush hulls and a somewhat modest draft, and some utilize multiple blade keels.
For an everyday cruising boat, a deep draft is usually better unless you frequently encounter reefs, sandbars, or other shallow water hazards.
Can You Reduce the Draft of a Sailboat?
Generally speaking, you can't dramatically reduce the draft of a fixed-keel sailboat. If your boat has a centerboard or a swing keel, you can dramatically reduce the draft by retracting it (just don't forget the rudder).
If you're looking to shave a couple of inches off the draft of your sailboat, try emptying the fresh and wastewater tanks and shedding unnecessary items. Don't try to remove any original ballast, as it could completely throw off the stability of your boat.
How to Beach a Deep-Draft Sailboat
Beaching is a fun way to berth your boat. Some sailboats are easy to beach (if they're designed for it), while others require great care. It's possible to beach a deep-draft sailboat, though it requires careful tide planning, terrain exploration, and some extra equipment.
A popular method is to use specialized poles. When you find a good beach, position your boat at high tide and deploy the poles, They'll settle and keep your boat upright when the tide goes out. This method isn't safe for all vessels, so intentionally grounding a deep-draft boat is generally best to avoid altogether,
