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’.