Speakers Bank is a large

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gro ...

structure in the Northwestern part of the

Chagos Archipelago The Chagos Archipelago () or Chagos Islands (formerly the Bassas de Chagas, and later the Oil Islands) is a group of seven atolls comprising more than 60 islands in the Indian Ocean about 500 kilometres (310 mi) south of the Maldives arc ...

. It is the northernmost feature of the archipelago, located at , 22 km Northwest of Blenheim Reef and is 44 km Northeast-Southwest, and 24 km wide. The total area is 582 km², most of which is water. Most of the rim of the reef is between 5.5 and 14.5 metres below water. In the south, near the southwest edge, there are some coral heads at 05°04'S, 072°16'E, 0.5 metres of which are dry during low tide, and over which the sea breaks heavily during the southeast

trade winds The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisp ...

. In the Northeast, at 04°47'S, 072°26'E, there are a number of drying cays, the biggest of which, Big Speaker Reef, just reaches the high water mark. The land area is negligible. Speakers Bank was surveyed in 1856 by British captain J. Speaker on HMS Wallerup. It is the site of many wrecks, also from prior times.

British Admiralty The Admiralty was a department of the Government of the United Kingdom responsible for the command of the Royal Navy until 1964, historically under its titular head, the Lord High Admiral – one of the Great Officers of State. For much of i ...

nautical chart A nautical chart is a graphic representation of a sea area and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land ( topographic map), natural features of the seabed, details of the co ...

11000030 - 3 Chagos Archipelago, Scale 1:360 000

References

External links

Indian Ocean PilotGeochronology of Basement Rocks from the Mascarene Plateau, the Chagos Bank and the Maldives Ridge
Atolls of the Chagos Archipelago {{BritishIndianOcean-geo-stub