a projecting fin-like plate fastened to the outside of the hull at the bilges to steady the ship at sea Source: Maritime Curators Group: Manual of Curatorship

Non-retractable elongated longitudinal fin protruding from the bilge used to reduce rolling.

    A keel attached to the outside of a ship's hull, near the turn of the bilge, to reduce rolling.  

An additional keel located near the bilge on either side of a vessel to protect the hull when grounding, and to lessen drift when heeling.

A long longitudinal fin fitted on the curved of a ship at the turn of the bilge to reduce rolling

A strake running along the ship's sides at the turn of the bilge, to reduce rolling of vessel

a non-moving stabilizer consisting of a pair (one on each side) of small keels or fins extending out at approximately 45° from a vessel's hull at the turn of the bilge in order to lessen or slow [..]

Two additional keels, one on each side of the main keel, that protect canvas-covered canoes.

fin or long strip of plate attached to the turn of the bilge and run in the fore and aft direction from 25% to 75% of ships length at both sides of a ships underwater body; bilge keels serve to reduce the rolling motion at sea