If you’re an avid scuba diver or snorkeler, you’ve undoubtedly heard about Blue holes. Blue holes are underwater caves or sinkholes which, from the top, appear circular and intensely dark blue. They’re often surrounded by lighter blue waters that are more shallow as well as sand, so they almost look like deep blue eyes in the middle of the ocean. Blue holes can occur all over the world, and some of the most famous are in the Bahamas, Belize and even Ohio.

There is often little oxygen in the deeper waters of these holes due to poor water circulation, so there’s often not very much sea life in the deeper deaths (there are  plenty of bacteria though!)

Here are some of the world’s more famous Blue holes:

Great Blue Hole in Belize

1. Great Blue Hole

This gorgeous blue hole is near Ambergris Caye in Belize. It’s an old sinkhole, and it’s over 980 feet across and 400 feet deep. Many, many tourists visit the site every year, and there is some wonderful coral and sea life to be enjoyed in the upper levels of the holes.You can go on a full-day dive trip to explore the hole, but keep an eye out for sharks! Most are harmless, but a few aggressive species are spotted here from time to time.

Corals in Great Blue Hole in Belize

2. Dean’s Blue Hole

This is the world’s deepest blue  hole, and it’s located in Long Island, Bahamas. The hole goes down for more than 660 feet! There are actually deeper water-filled blue holes, but Dean’s hole is the deepest one whose entrance is beneath the water. At almost 1,100 feet and 1,300 feet deep respectively, Zacaton in Mexico Pozzo del Merro in Italy are deeper, but you enter them above water.

Dean's Blue Hole, Bahamas

3. Blue Hole in the Red Sea

Divers love this location in east Sinai, near Dahab, Egypt on the coast of the Red Sea. The hole is about 500 feet deep, and there are plenty of fish and coral to enjoy. Only the most advanced divers attempt to swim through the Arch portion, but the rest of the hole is perfectly suitable for beginner divers.

Blue Hole in the Red Sea

Photos: Wikipedia Commons, jayhem, sunsetbeachvillabahamas, Wikipedia Commons