There are many blue holes in Long Island and the Bahamas. But none more famous than Dean’s Blue Hole located in a bay west of Clarence Town at the south end of Long Island. Deans is the deepest blue hole in the world with an underwater entrance. It plunges 202 meters, 663 feet to the bottom.
In prehistoric times, when sea levels were much lower, rainwater eroded extensive cave systems through the soft limestone base of The Bahamas. Diving enthusiasts can be thankful that when sea levels rose, these caves flooded, complete with their spectacular displays of stalagmites and stalactites. Where their massive ceilings collapsed, Blue Holes were created.
Dean’s Blue Hole is the deepest Blue Hole in the world, and the second largest underwater chamber. It is enclosed on 3 sides by a natural rock amphitheatre, and on the fourth side by a turquoise lagoon and powder white beach. Swell and wind don’t reach inside the Hole, and visibility is usually between 10 – 30 meters (30 – 100 feet). At the surface the Blue Hole is 25 x 35m (80 x 120 feet), but opens out after 20m (60 feet) into a cavern with a diameter of at least 100m (330 feet).