What is Freeboard?

• A. The rough measure of reserve buoyancy; distance in ft from the waterline to the weather deck
• B. The vertical distance from keel to hull bottom
• C. The horizontal distance from bow to stern
• D. The height of the superstructure

Answer: (A)

Freeboard is the vertical distance from the waterline up to the weather deck. This measurement reflects how much hull remains above the water and serves as a rough indicator of reserve buoyancy—the extra buoyant volume available if the vessel heels or takes on water. It’s a key factor in stability and compliance with load-line regulations.

The other common ship measurements describe different things: the distance from the waterline to the keel is draft (how deep the hull sits in the water), the distance from bow to stern is length, and the height of the superstructure is simply how tall the ship’s upper structures are. Those terms do not define freeboard.