Bahama Banks, Tongue of the Ocean, Bahamas.
Most of the Western Bahama Banks, the Tongue of the Ocean and Andros Island
(25.0N, 77.0W) as well as north central Cuba with its fringing reefs can be
seen in this one view. The green water over the banks is less than 30 ft.
deep but the deep blue of the Tongue is 4000 to 6000 ft. deep. All the
sediment on the banks, including the material that forms the islands, is
calcium carbonate (lime) precipitated from sea water by animals and plants.