Bilge keel

Although not as effective as stabilizing fins, bilge keels have a major advantage in their low impact on internal ship arrangements.

Unlike fins, bilge keels do not have any components inside the hull that would adversely affect cargo or mission spaces.

Also, a bilge keel should not protrude from the hull so far that the device could be damaged when the vessel is alongside a pier, even with a few degrees of adverse heel.

Note that small bilge keels are often fitted to smaller fishing boats precisely to protect the hull on drying moorings and to help keep the vessel upright.

Such an arrangement also enables the vessel to stand upright on firm sand or mud at drying moorings without the need for detachable legs, and is simpler than retractable fin keels while giving the hull greater protection.