Bassas da India is a French atoll that is about round in shape and is part of the French Southern and Antarctic Lands. The atoll is located in the southern Mozambique Channel, roughly midway between Mozambique and Madagascar, and about 110 kilometers northwest of Europa Island. Its rim averages around 100 meters in width and encloses a shallow lagoon with a depth of no more than 15 meters. The atoll is made up of eleven stony islets with no vegetation. The sea totally covers the reef from three hours before high tide to three hours after. The atoll has long been a marine risk and the scene of many shipwrecks because the area is also vulnerable to cyclones.