Located in the Lighthouse Reef Atoll of Belize where an island of coral encircles the shallow, light turquoise-colored waters of a lagoon is the Great Blue Hole, a huge submarine vertical cave that measures approximately 984 feet in diameter and 407 feet deep. With its beautiful, clear water and the variety of wild marine life residing in its depths, the enormous blue hole is a popular scuba diving destination. It is said that the deeper one goes, the water becomes more clear and the formations, more complex
Today’s blue holes were formed from erosion during previous ice ages when the Earth’s sea level was significantly lower than it is now. As the ocean began to rise, the cave system flooded and eventually collapsed, creating a “vertical cave” in the ocean. As such, the site is popular among divers, who flock to the area to see the geological formations that now lie in the ocean’s depths.
Although the Great Blue Hole is most definitely great, it is not the deepest. That title is held by Dean’s Blue Hole, located in the Bahamas, with a depth of 663 feet. For a demonstration on the magnitude of its size, check out Guillaume Nery, world champion freediver, as he does a freefall dive inside the hole in this video clip shot by fellow freediving champion, Julie Gautier.