Part of the Lighthouse Reef System, the famed Great Blue Hole is one of the most well known and photographed dive sites in the world. It is a large submarine cave about 45 miles off the coast of Belize, 1,000 feet across and over 400 feet deep, featuring stalactites and the occasional bull shark sighting. Jacques Cousteau’s name is frequently used in connection with the Great Blue Hole and he was one of its earlier explorers, visiting for the first time in the ’60s and again in 1972 when he returned with his research ship, the Calypso. The deepest depths of the Blue Hole are reserved only for experienced, certified divers who must still be accompanied by a dive master. However, snorkeling in the area around the Blue Hole is also available. Dive companies make daily trips from Ambergris Caye. Aqua Scuba Center offers complete packages beginning at $275.