A special type of drain for sailing dinghies in

which water is drawn out either by the attitude of the hull which causes it to

run aft, or by the lowered dynamic pressure on the outer skin resulting from

the high forward speed. Either of those conditions is best satisfIed when a

dinghy is planing. A cruising boat whose cockpit sole is several inches above

the waterline may have drains, and will usually be called ‘self-draining’,

though some people might call it self-bailing. But such simple drains are never

termed ‘self-bailers’.