Freeboard
From Wikipedia, the free encyclopedia
Freeboard, in sailing and boating, means the distance from the waterline to the upper deck level, measured at the lowest point where water can enter the boat or ship. A low freeboard is often found on racing boats, for speed. A higher freeboard will give more room in the cabin, but may compromise speed. A higher freeboard also helps prevent water from getting into a boat. A low freeboard boat is susceptible to swamping in rough seas. Warships use high-freeboard designs which improve seakeeping and stability, especially aircraft carriers, which must be as stable as possible to provide a good aviation platform.
Freeboard is also used to describe the height of an ice floe above the water surface. Freeboard does not include the potential snow coverage on the ice floe.
Freeboard in water channel design is the distance from the water level to the top of the channel's sides.