00:00One of the deepest marine sinkholes on Earth is open to anyone with a snorkel.
00:04Dean's Blue Hole on Long Island in the Bahamas is 663 feet deep.
00:09Its surface is about 82 to 115 feet across.
00:12Visitors wade through a few feet of water, and then the bottom simply vanishes.
00:17Sand from the shallows spills over the edge in long white streams, like underwater waterfalls.
00:22The writer saw schools of fish, three huge tarpon about 30 feet down, and a sea turtle.
00:28Free divers use it to chase records, and two Italian divers had just reached 40 meters, nearly 132 feet.
00:35Visitors can also jump off limestone ledges of about 15 feet.
00:39There are no fees, bathrooms, or lifeguards.
00:42A new sign installed in summer 2026 warns visitors to enter at their own risk.
00:48Disclosure. This video contains stock footage and content created or enhanced using AI-assisted tools.
