Blue Holes: Diving The Labyrinth (DVD)

Blue holes are underwater caves that can go hundreds, or even thousands, of feet down and feature a maze of passages and tunnels that act as liquid time capsules. National Geographic explorer and anthropologist Kenny Broad leads a team of divers and archaeologists to investigate these caves and unlock the mysteries of the ancient Bahamas, once teeming with life that quickly vanished. What caused these animals to disappear, and could 800-year-old human skulls provide the answer? Cave-ins, poisonous gasses, and the potentially deadly effects from depth pressure make cave diving a very dangerous sport - a lesson the team learns firsthand.