Reefs
Ledge Flats
Ledge flats are broad, low relief growths of massive coral
0.5-3.5 km wide and up to several km long, and are about 2-6 m deep. They
lack coral knobs of the other reef types but have sand floor depressions
tens of meters in diameter and several meters deep. These ledge flat reefs
form the elevated rim of the northern lagoon.