Blenheim Reef

Blenheim Reef is a partly submerged atoll structure in the Chagos Archipelago in the Indian Ocean, including the coral reef of Baxio Predassa on its southeastern rim along with a fully submerged section. It measures almost eleven kilometers north to south and more than four kilometers east to west, with a total area of 36.8 square kilometers, including an 8.5 square kilometer lagoon up to 18 meters deep. Only a few sand cays rise above the water on its eastern side, the largest being East Island at just under 200 meters long, and the fringing coral reef has a wide passage on the southwest side. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/