Dean's Blue Hole is located in Turtle Cove, Long Island. This grotto reaches 663 feet down and is currently the worlds deepest underwater sinkhole. In the 1600 - 1700's, it was a popular hiding place for pirates to keep their treasure. Many people go to the Bahamas just to see the stalagmites and stalactites, but some professional divers use it for competitions. November ,17th, 2013, Nicholas Mevoli attempted to dive to the bottom and back with no gas tank, or flippers. He dived 236 feet down and stayed underwater for 3 minutes, 38 seconds. After coming back up, he blacked out and died seconds later on that day (Sunday November, 17, 2013). The next day, his fellow teammates, competitors, and family gathered on the beach that the Blue Hole was located for a memorial.