either of two lengthwise fins attached along the outside of a ship's bilge; reduces rolling

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

One of a pair of longitudinal plates that, like fins, project from the sides of a ship or boat and run parallel to the center keel. They are intended to check rolling. On large ships the outward projections of the bilge keels may be slight; on small yachts they may be comparatively deep.

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

A long longitudinal fin fitted at the turn of the bilge to reduce rolling.