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 vesse ...

) of

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

from the water surface to the

keel The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. As the laying down of the keel is the initial step in the construction of a ship, in Br ...

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