Virgin Deep Flight Challenger, submersible from one of possibly four attempts to return to the bottom of the Mariana Trench

Fifty two years ago, U.S. Navy Lieutenant Don Walsh and oceanographer Jacques Piccard dove to the bottom of the Mariana Trench in the bathyscaphe Trieste. They were the first, and so far, the only humans to have ventured to the deepest spot in all the the world’s oceans.  Now three and possibly four teams are preparing to return to the depths of the Mariana Trench.

The vessels planning to return to the deepest place on earth include a three man submarine designed and built by Triton Submarines; a one man submarine, the Virgin Deep Flight Challenger, sponsored by Richard Branson’s Virgin Group, designed by Graham Hawkes, and to be piloted by Chris Welsh; and a submarine with a two or three man crew developed by DOER Marine. Hollywood director James Cameron is also understood to be preparing for a descent.

The Mariana Trench is deep. Really, really deep. The submersibles will be diving deeper than most planes fly high. The deepest part of the Mariana Trench is almost 36,000 feet (5.9 MN) deep. By comparison, most commercial airliners fly at a cruising altitude of 30,000 feet above sea level. If Mount Everest was placed upside down in the Mariana Trench, the base would still be 6,670 feet underwater.  The water pressure at the bottom of the trench is 15,750 psi, or over 1,000 times atmospheric pressure at sea level.

Why dive so deep? The answers vary from the ultimate adventure-tourism, to scientific research to simple bragging rights.

Triton Submarine‘s aim is commercial: the team plans to put tickets on sale for those who want to take the dive.

Bruce Jones, the company’s chief executive, said: “You have thousands of people that climb Everest, and Richard Branson is taking tonnes of deposits for trips into near-Earth orbit.

“We think you can get $250,000 from some real adventuresome types to say they’re one of a handful of people who’ve been to the deepest spot in the ocean.”

Virgin’s Deep Flight Challenger team wants to dive the four deepest trenches in the world. The submersible, designed by British engineer Graham Hawkes, was originally built for billionaire adventurer Steve Fossett, who died in a plane crash. It was then purchased by former property investor, Chris Welsh, who now plans to make the solo dives himself.

“The rewards of this is breaking ground in so many ways – in raw human exploration, on bringing back science, and in getting a better understanding of our world,” Welsh said.

Welsh hopes to pilot the one person sub to the bottom of the trench, and break the record for the first lone dive there, later this year.

DOER Marine is designing a submarine for scientific exploration, supported by a large donation by Eric Schmidt, the chairman of Google.  The design is some years away from its first dive.

Film director James Cameron is reported to also be preparing an attempt on the trench,though information on his sub remains a closely guarded secret.

Race to the bottom of the ocean

Thanks to Alaric Bond for passing the news along.