Blue Holes And Spectacular Coral Reefs, Andros, Bahamas

Dean's Blue Hole is the world's deepest known blue hole with seawater. It plunges 202 metres (663 ft) in a bay west of Clarence Town on Long Island, Bahamas.
Andros Island is the largest island of the Bahamas and North Andros is the sixth largest island in the West Indies at roughly 6,000 km2 (2,300 sq mi) in area and 167 km (104 mi) long and 64 km (40 mi) wide at its widest point. It is actually composed of three major islands: North Andros, Mangrove Cay, and South Andros. The island has the world's third largest barrier reef, which is over 225 km (140 mi) long. It is affectionately known by Bahamians as the "Big Yard". Andros is the least densely populated of all the Bahamas, with a population of a little over six thousand. Most of these people live on the east coast of the island in the three major towns on the island; Nicholls Town and Andros Town on North Andros, and Congo Town, on South Andros.