ABOUT THE BLUE HOLE
The Great Blue Hole is a large submarine sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 70 kilometers from the mainland and Belize City. The hole is circular in shape, over 300 meters across and 125 meters deep.
Besides modern-day marine life, this vertical cave contains remnants from its days above water. When much of Earth’s water was sequestered in glaciers, global sea level was lower. During this time, stalactites or “dripstones” formed inside this cave, and those rocks are preserved underwater today.
Jacques Cousteau revealed the secrets of the mysterious Blue Hole to millions of viewers in 1971 through the television series The Undersea World of Jaques-Yves Cousteau. Today, dive boats follow the way of the famous Calypso to explore one of the world’s best destinations for scuba diving.
Blue Hole Natural Monument is one the seven wonders of Belize’s World Heritage Site. The Belize Barrier Reef Reserve System, which covers a total area of 963 square kilometers, illustrates a classic example of reefs through fringing, barrier, and atoll types.
The coastal area of Belize is an outstanding natural system consisting of the largest barrier reef in the northern hemisphere, offshore atolls, several hundred sand cays, mangrove forests, coastal lagoons and estuaries. The system's seven sites illustrate the evolutionary history of reef development and are a significant habitat for threatened species.
The reef extends from the border with Mexico to the north, to near the Guatemalan border to the south. The Belize submarine shelf and its barrier reef, represent the world second largest reef system and the largest reef complex in the Atlantic-Caribbean area. Outside the barrier, there are three large atolls: Turneffe Islands, Lighthouse Reef and Glover's Reef.
Between the mainland and the barrier reef is an extensive offshore lagoon which increases in width and depth from north to south. In the north, water depth averages 2-3 m over a flat, featureless bottom 20-25 km wide. South of Belize City, the shelf gradually deepens forming a channel between the mainland and the outer platform, reaching a depth of 65 m in the Gulf of Honduras.
The approximately 450 sand and mangrove cays confined within the barrier and atolls range in size from small, ephemeral sand spits to larger, permanent islands capable of sustaining human settlements. The largest of these Islands is Ambergris Caye where the village of San Pedro is located. Several PADI dive operators visit Half Moon Caye Natural Monument out of San Pedro, Caye Caulker and Belize City.
The Great Blue Hole is a popular spot amongst recreational scuba divers, who are lured by the opportunity to dive in crystal-clear water and meet several species of fish, including giant groupers, nurse sharks and several types of reef sharks such as the Caribbean reef shark and the Blacktip shark. Other species of sharks, like the bull shark and hammerheads, have been reported there, but are not regular sightings. Usually, dive trips to the Great Blue Hole are full-day trips, which include one dive in the Blue Hole and two further dives in nearby reefs.