Great Belize Blue Hole

The Great Blue Hole is a world-class destination for recreational scuba divers attracted by the opportunity to dive in crystal-clear waters and see myriad species of marine life including tropical fish and spectacular coral formations.

The marine life in these areas includes nurse sharks, giant groupers, and several types of reef sharks such as the Caribbean reef shark and the Blacktip shark. Dive excursions to the Great Blue Hole are full-day trips, that usually consist of one dive in the Blue Hole and two additional dives in nearby reefs. The Great Blue Hole is in our list of Top 10 Reasons Why You Should Visit Belize.

The Great Blue Hole is a large underwater sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 100 kilometres (62 mi) from the mainland of Belize City.

The hole is circular in shape, over 300 metres (984 ft.) across and 125 metres (410 ft.) deep. The world’s largest natural formation of its kind, the Great Blue Hole is part of the larger Barrier Reef Reserve System, a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization (UNESCO).

Glyn Collinson, a NASA scientist who recently dived the Great Blue Hole described it thus:

“It was the deepest, deep blue hole imaginable; A chasm that fell away deep into the deep, dark blue. It had been forged out of solid rock as caverns, hundreds of thousands of years ago during the last ice age. For eons, water filtered through the rock and into these great stone cathedrals, breeding multicolored stalactites and stalagmites. Then, one by one they collapsed in on each other, creating a chasm four hundred feet deep. As Earth’s swollen polar ice-caps receded, the warm Caribbean ocean swept in to fill the chasm with boiling white hands, the last rays of sunlight struck the chasm’s floor. Then, as the limestone broke down, it began to rain tiny fragments of rock, which slowly began to fill the great Blue Hole.”

“Alright,” the dive master said, jolting me back to reality. “Welcome to the Blue Hole. This one is real deep, starting with a drop off from forty feet that goes right the way down to the bottom past 400 feet.” The man held up a detailed custom drawn map of the site and pointed as he talked. “We will go down fast to one hundred and thirty feet where stalactites come down from this overhang. We will stay there for a maximum of twelve minutes, starting from the time that the first pair gets there. We all need to keep together and watch each other. To make sure that you all keep an eye on your depth, the dive pair who goes the deepest will buy a round of drinks for everyone back at the Island.” ‘Great’, I thought, ‘so much for pushing our depth limits.’

Noted SCUBA diver, writer and photographer Rick Frehsee wrote the following account of his research on the Great Blue Hole:

Origin of the Belize Atolls

“Lighthouse Reef, Glover’s Reef and the Turneffe Islands are all distinct anomalies in the Caribbean. Nothing else in the Western Hemisphere resembles a true coral atoll, except perhaps Chinchorro Reef, off Mexico’s southern Yucatan Peninsula (just above the Belize atolls). According to geologists they are even more unusual in that the origin of their formation does not seem to mirror the atolls of the Pacific Ocean, where rings of coral are better known.

“The ancient processes contributing to Belize atoll development may have begun as many as 70 million years ago and the atolls did not develop around subsiding volcanoes. Instead, they originated atop giant fault blocks; limestone covered ridges that settled in steps, providing a series of offshore platforms for coral growth. After the last ice age, with the slow rise of sea level, coral growth continued upward, creating the precipitous outer walls and the shallow inside lagoon that typifies these distinct formations. Many drop-offs surrounding the Belize atolls are thousands of feet deep, while depths in the shallow lagoons average 10 to 30 feet.”

Recent History: Belize Atolls and Great Blue Hole First Explored By Jacques Cousteau

“The sense of isolation and remoteness that accompanies a visit to the atolls, belies a rich history. Although only archaeological traces remain, it appears the ancient Maya inhabited at least a few of the atoll islands for more than 1,000 years. The recorded history of the atolls begins in the early 16th century with the arrival of the Europeans. From 1528 to 1532 Spanish explorers researched and and charted the coastline and offshore reefs of Belize and the Yucatan.

“Original names known to the indigenous inhabitants or given by the first Spanish explorers are now obscured. The only names that have survived are published on charts discovered decades after their making. It appears that Turneffe used to be called Terre Nef; Lighthouse Reef, Quattro Cayas (four cayes) or Eastern Reef; and Glover’s Reef, Longorif. The present names evolved with English discovery and occupation in the 1750s. Glover’s Reef was named for the English pirate John Glover, who used this particular atoll as a hideout. Lighthouse Reef was renamed after a navigational light was permanently established on Half Moon Caye.”

In 1836 the famous biologist-evolutionist Charles Darwin paid homage to these remarkable formations when he said the Belize atolls and the Belize Barrier Reef constitute “..the richest and most remarkable coral reefs in the entire western Caribbean.”

In the mid 1970s Jacques Cousteau’s Calypso made its famous investigation of the Great Blue Hole and the Belize atolls, which corresponds to the arrival of dive travel to the region.

Blue Hole Experience from Captain Ray Auxillou

Canadian-Belizean diver Captain Ray says: “I was one of those early arrivals from the scientific and sport diving community, accompanying the Cousteau divers into the Blue Hole and participating in one of the first dive travel ventures along the Belize River.

“Because of the relative isolation, our atolls have remained nearly as pristine as I remember them 30 years ago. As a result of today’s relatively easy travel, this sense of remoteness and the quality of the underwater environment is even more extraordinary. With only a few exceptions, I can visit any above or underwater site in the Belize atolls and the scene appears unaltered.”

On-shore caves of similar formation, as large collapsed sinkholes, are well known in Belize, and in the Yucatan Peninsula, where they are known as “cenotes”.