Nearly 50 years ago, legendary explorer Jacques Cousteau propelled the Great Blue Hole to fame.
A diver's paradise, the marine sinkhole is surrounded by abundant corals and sparkling turquoise waters. Located off the coast of Belize, the Great Blue Hole is the biggest ocean sinkhole in the entire world at just less than 1,000 feet wide and more than 400 feet deep.
The hole's unparalleled beauty, as well as the irresistible mystery of what lies at the bottom, have lured many divers. Unfortunately, not every explorer who dared to venture into the depths was able to come back up to the surface.
A Journey Down The Great Blue Hole
Last December 2018, a handful of notable scientists and personalities set out on a diving expedition into the famed sinkhole. Led by Aquatica Submarines, the team included billionaire Richard Branson, Cousteau's grandson Fabien Cousteau, and National Geographic explorer Erika Bergman, among others.
Valuable photographs, maps, and even an informative mini-documentary resulted from the expedition. Bergman, who is also a submersible pilot for Aquatica Submarines, talks about the discoveries they unearthed during their journey in an interview with Newsweek.
It turns out that at the depth of 290 feet, there is a layer of hydrogen sulfide, which is known mostly as a colorless, flammable, and toxic gas, enveloping the entire hole. No marine life gets through this toxic layer.
"Anything that fell into the hole decomposed until that process used up all of the oxygen below 290 feet," Bergman explained, adding that there is no oxygen below the layer, so any living thing becomes preserved.
"Without oxygen, nothing survives," she continued. "Beneath the hydrogen sulfide layer it is very dark. Looking straight up from inside the submarine you can just barely make out the circular opening of the hole, all of the light pouring into the hole is shut out by the thick chemical layer."
Beyond this layer? A sinister graveyard.
Long-Lost Corpses Finally Found
Lying at the bed of the Great Blue Hole are corpses of marine life, mainly hundreds of conchs. In a blog post, Bergman recalls seeing track marks of conchs trying to escape what the scientists call the Conch Graveyard.
Bergman and the rest of the team also found old scientific equipment as well as GoPro with retrievable footage. Here, there are also two dead bodies of long-lost divers out of what's believed to be three people who have gone missing in the sinkhole.
"We found kind of the resting place of a couple folks, and we just sort of very respectfully let the Belize government know where we found them, and everyone decided that we would just not attempt any recovery," she told in Business Insider. "It's very dark and peaceful down there, just kind of let them stay."