The Chagos Archipelago.(Atolls with areas of dry land are named in green)
The entire land area of the islands is a mere 63.17 km², with the largest island, Diego Garcia, having an area of 27.20 km². The total area, including lagoons within atolls, however, is more than 15,000 km², of which 12,642 km² are accounted by the Great Chagos Bank, the second largest atoll structure of the world (after the completely submerged Saya de Malha Bank). The shelf area is 20,607 km², and the Exclusive Economic Zone, which borders to the corresponding zone of the Maldive Islands in the north, has an area of 636,600 km² (including territorial waters).The largest individual islands are Diego García (27.20 km²), Eagle (Great Chagos Bank, 2.45 km²), Île Pierre (Peros Banhos, 1.50 km²), Eastern Egmont (Egmont Islands, 1.50 km²), Île du Coin (Peros Banhos, 1.28 km²) and Île Boddam (Salomon Islands, 1.08 km²).
The number of atolls in the Chagos Islands is given as four or five in most sources, plus two island groups and two single islands, mainly because it is not recognized that the Great Chagos Bank is a huge atoll structure (including those two island groups and two single islands), and because it is not recognized that Blenheim Reef has islets or cays above or just reaching the high water mark.
In addition to the seven atolls with dry land reaching at least the high water mark, there are nine reefs and banks, most of which can be considered permanently submerged atoll structures.
Resources
The main natural resources of the area are coconuts, and fish and the licensing of commercial fishing provides an annual income of about two million dollars for the British Indian Ocean Territory authorities.
All economic activity is concentrated on the largest island of Diego Garcia, where joint UK-US military facilities are located. Construction projects and various services needed to support the military installations are done by military and contract employees from the UK, Mauritius, the Philippines, and the US. There are currently no industrial or agricultural activities on the islands. All the water, food and other essentials of daily life are shipped to the island. An independent feasibility study led to the conclusion that resettlement would be "costly and precarious". Another feasibility study, commissioned by organisations supporting resettlement, found that resettlement would be possible at a cost to the British taxpayer of £25 million. If the Chagossians return, they plan to re-establish copra production and fishing, and to begin the commercial development of the islands for tourism.
Climate
Tropical oceanic climate; hot and humid but moderated by trade winds. Climate is characterised by plenty of sunshine, warm temperatures, showers and light breezes. December through February is considered the rainy season (summer monsoon); typical weather conditions include light west-northwesterly winds and warmer temperatures with more rainfall. June to September is considered the drier season (winter), characterised by moderate south-easterly winds, slightly cooler temperatures and less rainfall. The annual mean rainfall is 2600 mm (100 inches), varying from 105 mm (4 inches) during August to 350 mm (14 inches) during January.
