Cauvin Bank is a wholly submerged atoll structure in the Southern Part Chagos Archipelago at (6°49′S72°22′E), just about 7 km South of the Southeastern corner of the rim of the Great Chagos Bank. It is roughly circular in shape, with a diameter of 4 km, and an area of about 12 km². There are least depths between 9 and 11 m in the Northern part of the reef.