Definition of Draft

Draft, or draught, refers to the vertical distance between the waterline and the bottom-most part of the boat’s hull (keel). The keel provides a counterweight to the forces of the sail, helping to keep the boat afloat.

Once the boat is underway, the lower the keel sits in the water, the deeper the draft is, meaning the boat is much more stable in open seas.

draft marks on ship’s bow

Draft determines how and where you can use your boat because it indicates:

  • The minimum depth of water needed for the boat to float freely without touching the sea floor
  • How much cargo you can safely carry on your boat without throwing off the center of gravity

In relation to lighting your boat, the type of keel and draft of a boat may affect your choice of underwater lights.

For example, you might choose the low profile, flush mount option for the Seablaze Typhoon Thru-Hull Underwater light if your boat has a shallow draft. On the flip side, if your boat sits deep in the water, the surface mount works just as well.

Example of Draft in a Sentence

"The captain carefully calculated the boat's draft before entering the shallow bay to avoid running aground on the sandbar."

Synonyms: draught

Related Terms for Draft