|Dean's Blue Hole|
|Location||Clarence Town, Long Island, Bahamas|
|Depth||202 metres (663 ft)|
Dean's Blue Hole is a blue hole located in The Bahamas in a bay west of Clarence Town on Long Island and is the world's second deepest, after the Dragon Hole in the South China Sea, with a depth of 202 metres (663 ft).
A blue hole is a water-filled sinkhole with the entrance below the water level. They can be formed in different karst processes, for example, by rainwater soaking through fractures of limestone bedrock onto the watertable. Sea level here has changed: for example, during the glacial age during the Pleistocene epoch (ice age), some 15,000 years ago, sea level was considerably lower.
Dean's Blue Hole is roughly circular at the surface, with a diameter ranging from 25 to 35 metres (82–115 ft). After descending 20 metres (66 ft), the hole widens considerably into a cavern with a diameter of 100 metres (330 ft).
- Wilson, William L. (1994). "Morphometry and Hydrology of Dean's Blue Hole, Long Island". Bahamas Journal of Science. 2 (1): 10–14. Archived from the original on 7 March 2012.