- A ridge of coral - A ridge of rocks, coral or sand at the water's edge - Area of shallow water - Coral bar - Gold-bearing vein - Great Barrier ... - Knot to be avoided by sailors
- Sliding keel - A movable or sliding keel formed of a broad board or
slab of wood or metal which may be raised into a water-tight case
amidships, when in shallow water, or may be lowered to increase the
area of lateral resistance and prevent leeway when the vessel is
beating to windward. It is used in vessels of all sizes along the coast
of the United States