The Great Blue Hole is a large underwater sinkhole off of the coast of Belize. It lies near the center of Lighthouse Reef atoll about 65 miles from Placencia.
It was formed as a limestone cave system during the last ice age when sea levels were much lower. As the ocean began to raise the caves flooded, and the roof collapsed.
In past years diving The Great Blue Hole meant visiting Ambergris Caye, Caye Caulker, or Belize City. Now you can dive the pristine southern reef of Belize and include the Blue Hole as part of your vacation.
The hole is almost perfectly circular, over 1,000 feet across and 400 feet deep, and is almost surrounded by fringing reefs which make for an excellent snorkel adventure.
While the snorkelers explore the fringing reefs, divers descend along the wall to a depth of 130 feet. At a depth of 120ft divers can clearly see the stalactites which were form from dripping water when the cave was above sea level.
The second dive is done at Half Moon Caye Wall which is known for its abundance of Marine life. The seascape is cover with varieties of sponges, sea fans, and a wide variety for corals which makes for a kaleidoscope of colors.
Between or second and third dive we visit Half Moon Caye National monument for lunch on the beach. The most famous inhabitants of this island are its Red- footed Boobies and Frigate birds which nest on the caye. There is viewing platform in the heart of the colony that lets you enjoy the birds from up close.
The Third dive is done at the Aquarium. The site is named for the wide variety of small resident reef fish on the reef top and along the edge of the wall.