KEEL - The centerline of a marine vessel running fore and aft; the backbone of a vessel.

KETCH - A sailing craft with two masts, a main mast, and a shorter mizzen mast aft of the main mast.

KILO - Letter K in the Marine Radio Alphabet.

KNOT - A measure of speed equal to one nautical mile (6076 feet) per hour.

KNOT - A fastening made by interweaving rope to form a stopper, to enclose or bind an object, to form a loop or a noose, to tie a small rope to an object, or to tie the ends of two small ropes together.