Freeboard is the measurement given from the waterline to the top of a boat’s sides or deck. In this battle of the boats we look at high freeboard vs low freeboard to see the benefits and drawbacks of each.
High freeboard on a boat gives the deck more protection against spray because it raised high above the water line. Low freeboard means the deck is closer to the waterline and experiences much more spray much the boat has more speed. High freeboard is better for boats that navigate choppy waters. Low freeboard is better for shallow draft boats that are used in shallow inland bodies of water. However, a racing sailboat used in the ocean will have low freeboard because this makes the boat faster.
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What’s all this about freeboard?
Freeboard is a much misunderstood concept, even by guys that have been boating for years. Now this does not mean those boat enthusiasts with 20+ years water experience do not understand the mechanics of freeboard; many are just unsure of the meaning of the word.
So, let me cover quickly exactly what the word freeboard means and what it measures before we look at the pros and cons of high and low freeboard boats.
Freeboard is the distance from the waterline to the top of a boat’s sides or deck. It layman terms all this means is that freeboard is measuring the distance from the waterline to the point on the boat that is most susceptible to taking on water
High freeboard on a boat means the deck, and the sides of the boat, are high above the waterline. Some boats, such as oil tankers and cruise ships, have a very high freeboard.
Low freeboard on a boat means the deck, and the sides of the boat, are much closer to the waterline. Some boats, like a Jon boat, have a very low freeboard.
Be aware that although there is high freeboard and low freeboard, the freeboard of a boat is not a fixed measurement.
Weight on the boat has an affect on how low the boat sits in the water and thus on its freeboard. If a boat is fully loaded then the distance between the deck and the waterline will be reduced. This is less of a problem with high freeboard boats than it is with low freeboard boats for reason you are about to find out.
High freeboard
There are some key reasons why you may want a high freeboard boat but there are just as many reasons why you may not want one.
Freeboard differs on different types of boats and high freeboard is not just seen on one type.
Although most high freeboard boats you will see are found in open ocean water it is not unusual to see a non-seaworthy boat, that is mostly used on inland waters, with a high freeboard.
Many skiffs are designed with a high freeboard because they are used in open lakes and large bodies of water that experience a lot of chop. Even many flat bottom skiffs that are designed to be used in the shallows will have freeboard.
High freeboard advantages
The main advantage of high freeboard is protection from spray.
The high sides of the boat, and high bow and stern, mean that less spray makes it into the boat. This means boating in choppy water is less of a wet experience for people on the boat.
Many deep draft boats that navigate ocean waters will have high freeboard to minimize the amount of water that gets on the deck. It should be fairly clear why large ships like ocean-going cruisers have high freeboard.
Tankers and military ships use high freeboard more for the increased buoyancy and deck space it offers than to protect against water on the deck.
If you regularly boat in choppy water then a boat with high freeboard is better suited to your needs than a boat with low freeboard.
A boat boat with high freeboard makes it easier to boat in challenging conditions, though this hull characteristic is usually accompanied by deep draft. For an explanation of deep and shallow draft read this.
High freeboard disadvantages
High freeboard boats are slower than low freeboard boats.
The high freeboard gives more room on the deck of the boat but will increase its weight and create drag, thus making the boat slower.
High freeboard is also usually accompanied by a deeper draft making shallow water navigation difficult or impossible.
Shoal draft boats, that are used in the ocean but also need a shoal draft so they can access shallow areas of water near submerged banks and shoals, will comprise somewhat between high freeboard and low freeboard but for the most part you will rarely see high freeboard on a boat that goes into the shallows.
Low freeboard
There are many reasons why you would want a boat with low freeboard and, of course, just as many reasons why you wouldn’t.
These advantages and disadvantages apply to both seaworthy boats and non-seaworthy boats which are mostly used on inland bodies of water.
Low freeboard advantages
Many shallow water boats will have low freeboard.
Although some shallow water river boats will have a fairly high freeboard almost every flat bottom shallow water boat will have a low freeboard. Even inland-water boats that are designed to be used in rougher water will have a low freeboard because it helps to keep the boat’s draft shallow.
But, it’s not just about draft.
Low freeboard on a boat usually equates to more speed. There is less weight and less drag on a low freeboard boat than there is on a high freeboard boat and thus the boat can move faster in the water. This is why you will see many seaworthy racing sailboats with low freeboard.
With shallow draft boats, such as Jon boats and flat bottom skiffs, challenging conditions are seldom encountered because they are used on inland bodies of water that are more protected from strong winds. Therefore they are better suited to low freeboard because it makes them faster and allows them to have a shallower draft for accessing shallow water areas.
Jon boats, for example, have such a shallow draft, due to their flat bottom and low freeboard, that they can be used to navigate marine areas with just 2″ of water. They are also very easy to get on plane and offer an incredibly smooth ride on calm water even at high speeds.
If you regularly boat on calm inland waters, and access the shallows, then a low freeboard boat is better suited to your needs.
The low freeboard helps reduce boat weight and keep the draft shallow. It also makes it is easier to get the boat on plane.
Low freeboard disadvantages
The most obvious disadvantages of having low freeboard on a boat is the restrictions it places on your boating activities. Low freeboard boats are dry in fine weather but once some chop shows up the deck gets wet fairly quickly.
As many vessels with low freeboard also have shallow drafts it makes these boats unsuitable for ocean use. Of course there are exceptions such as racing sailboats and some people will even take their Jon boats into the ocean but low freeboard and ocean swell do not mix well.
Low freeboard boats, like Jon boats, and rough water do also not mix well for the same reasons.
Another major disadvantage of low freeboard is weight restrictions on the boat.
As the top of the hull sits very close to the water the weight capacity of the boat must be strictly observed as overloading the boat will put it’s deck dangerously close to the waterline. This can only result in the boat taking on water and probably sinking. For this reason it is much more common to see low freeboard on vessels that are used on calm inland waters.