- 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
- A plank fixed beneath an object, as beneath the rudder of a
vessel, to protect it from injury; a plank on the ground under the end
of a shore or the like.
- See Shoal.
- of Shoal
- Becoming shallow gradually.