South Soudan is the largest of the banks, with many reefs and passes.
West Soudan is small, rocky, and shallow, and is the least fished of the banks.
East Soudan, until the 1970s, was considered to be a completely different formation altogether, since it is located more than 100 miles away from the other banks.
The other banks are closely linked, separated by small shallows or channels.
Two million years ago, Soudan was a large island, as were Nazareth, Cargados Carajos and Saya de Malha.