Richard Branson takes a submarine in the biggest chasm of the world

IAt first, it's like a giant ink spot and flat in the sea, but below this pit – the largest in the world – is a cave big enough to engulf two Boeing 747s with enough space.

The famous marine explorer Jacques Cousteau did not discover the chasm, located in the Caribbean Sea off the coast of Belize, but he named it "The Great Blue Hole" in 1971 and has since attracted divers.

In his first mission, Cousteau's grandson and Sir Richard Branson sink into a dark background and dive into a submarine as part of an expedition that will be broadcast live and broadcast around the world on Discovery Channel .

It will be a feat. Scuba divers usually go down only to a maximum depth of 130 feet under water. What lies beneath this territory remains largely unexplored, and much remains.

Branson and Fabien Cousteau will join Erika Bergman, chief pilot of Aquatica Submarines, and will make several expeditions into the chasm this weekend in a remotely piloted Stingray 500 submarine, to collect data and map the submerged cave.

Some 100,000 years ago, this natural wonder was a network of caves located above sea level, with suspended ceilings with stalagmites and limestone stalactites. Over time and during the last ice age of our planet, the rise in sea level finally flooded the structure and it collapsed to form the chasm that she is today.

Scientists used sonar to measure the Great Blue Hole in 1997, but this will be the first exploration since and by far the most thorough.

The Bergman team hopes to gather scientific data on marine aspects, including water quality and bacterial activity, in order to obtain high resolution sequences and a detailed plan of the internal structure of the hole for the first time.

Curiously, they seek to discover what it is theorized to establish at its base, a layer of depleted oxygen, which could offer essential clues to the environmental forces potentially linked to the fall of the Mayan civilization between 800 and 1,000 A.D.

"One of the most exciting brands that we are really excited to do is the oxygen test," Bergman told Endgadget. "We have heard that in the Blue Hole there is an anoxic layer near the bottom [and] things do not break down in anoxic areas so we can find a life preserved. "

Branson hopes that his participation in the project will raise awareness about ocean conservation and supports the goal of protecting at least 30% of the ocean from here. 2030.

The broadcast will be broadcast live on the Discovery Channel from 9:00 pm to 11:00 pm on Sunday, December 2, and Richard Branson will talk to Telegraph Travel about what the team will discover next week.