Keel depth (sometimes given as Depth to keel) is the depth (or

draft Draft, the draft, or draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a v ...

) of

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

from the water surface to the

keel The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often ...

of a vessel, the deepest part. The keel establishes a commonly defined reference point to measure to. Keel depth is useful for determining safe operating depth in shallow water.

References

A WW II submarine depth gauge displaying "Depth to keel"
{{Submarine-stub Nautical terminology Ship measurements