Just off the coast of Belize lies a mysterious formation at the bottom of the ocean. The shallow waters of the reef plunge hundreds of feet down into a massive void, appropriately named the Great Blue Hole, into which very few people have ventured.

Remains Of The Past

The origins of the Great Blue Hole, while interesting, aren’t much of a mystery. During Earth’s ice ages, sea levels were much lower. What is now shallow waters off the coast of Belize was once dry land. Throughout Earth’s last several ice ages, a massive sinkhole formed a cave. That cave filled with water and eventually became the Great Blue Hole.

When you get right up close to it, the massive underwater cavern looks somewhat intimidating. The shallow ocean drops off into a deep blue chasm, the bottom of which cannot be seen from the surface. At around 410 feet deep, the Great Blue Hole remained a mystery for some time until a handful of intrepid divers made their way to the bottom.

A Long Way Down

Diving 400 feet below the surface not only takes experience and courage. It’s a journey that requires special equipment to provide enough oxygen to last the entire trip. For reference, standard diving gear only allows the wearer to explore down to about 130 feet. In late 2005, a team of divers from The History Channel set out on the first documented dive to the bottom of the Great Blue Hole.

Their adventure into the belly of the beast confirmed the fact that the cave had been created as a dry landform before being submerged underwater and reemerging again on several occasions to continue its formation. When they finally reached the bottom, the divers landed in soft sediment, which had been deposited by the currents in uneven dunes. Stalactites loomed from overhangs, indicators of a damp past above water. Markings on the rocky formations indicated a series of rising water levels throughout several major climate phases earlier in Earth’s history.

Unusual Finds And Future Adventure

In addition to finding a cave at the bottom of the deep oceanic hole, the divers also found an assortment of crabs strewn about the sand, all of which were dead. The Deep Blue Hole receives minimal circulation in its waters 400 feet from the surface. As a result, they hold very little oxygen. Any creature unlucky enough to tumble in from up above is doomed to meet a grisly demise. Another side-effect of anoxic water is that not much can survive down there to break down dead creatures, so the carapaces stayed behind, preserved after death.

Since 2005, no one has documented another trip to the bottom of the Great Blue Hole. Jacque Cousteau, who originally made the place famous in 1971, and the team from the History Channel are the only people to ever truly explore it. Now, Cousteau’s son, Fabien, plans to explore the depths and gather information from the rock and sediment. His expedition will be documented on the Discovery Channel and will help scientists better understand the geological history of the area.