Bassas da India (also called Basse de Judie) is an uninhabited, roughly circular atoll about 10 km in diameter, which corresponds to a total size (including lagoon) of 80 km². It is located in the southern Mozambique Channel, about half-way between Madagascar (which is 385 km to the east) and Mozambique, and 110 km northwest of Europa Island. It rises steeply from the seabed 3000 m below. The reef rim averages around 100 m across and completely encloses a shallow lagoon that has a maximum depth of 15 m. Its Exclusive Economic Zone (EEZ) of 123,700 km² is contiguous with that of Europa Island.
The atoll consists of ten barren rocky islets, with no vegetation, totalling 0.2 km² in area. Those on the north and east sides are 2.1 to 3 m high, and those on the west and south sides 1.2 m. The reef is completely covered by the sea from 3 hours before to 3 hours after high tide. The coastline of the reef measures 35.2 km. The region is subject to cyclones. The atoll has long been a maritime hazard and is the site of numerous shipwrecks.
Apparently this reef was renamed Bassas da India by subsequent cartographers owing to mistakes in their writing the word "Judia" by confusing letters while copying former maps (Capital "J" changed to "I" and "u" to "n").