"We have 800 pounds (362kg) of moon rocks and not one drop from the bottom of the ocean," said Alex Tai, Virgin Group director of special projects.
The dives will be dangerous and the pilots will likely be down in the dark and cold ocean depths for hours with little communication with the outside world. Rescues will be impossible, Welsh said. Still, he was clearly more excited than wary of the prospect, saying there is a magic to exploring new places.
"It's like going to the moon and having the lunar rover to explore around," Welsh said.
The dives also will be recorded and uploaded to Google Earth, said John Hanke, the internet search engine's vice president of product management.
"Our mission for Google Earth is to create an interactive virtual globe and enable users to visit places that they've never explored, including the world's oceans," he said.
The submarine originally was commissioned by Branson's close friend and fellow adventurer Steve Fossett, who died in 2007 while flying a plane over the Sierra Nevada. Fossett had intended to complete the first solo dive to the Mariana Trench, Branson said.
Branson also said he plans to create a larger submarine that can hold more people and offer trips to tourists for a sizable fee.
Last year he unveiled a three-person submarine called the Necker Nymph, which is available for $US2500 ($2420) a day for guests of his private resort in the Caribbean. The submarine, created by San Francisco-based Hawkes Ocean Technologies, is capable of going almost 100 feet (30 metres) deep. In a subsequent interview with Popular Mechanics, Hawkes officials said they were also working with Branson on submersibles capable of high-speed deep sea travel.
Branson has also been working on a space tourism venture with the construction of a $US209 million ($202.3m) spaceport in New Mexico. The British businessman has said he expects to launch the first suborbital flights from Spaceport America between mid-summer 2011 and spring 2012. Many of the 500 people that have signed up to be astronauts have expressed interest in being "aquanauts", he said.
While most of the country is still dealing with the daily realities of a struggling economy, University of California, Berkeley professor Robert Reich said the super-rich are richer today than they have ever been and there is a market in selling them new adventures.
High-end retailers such as Tiffany & Co. and Neiman Marcus continue to do well despite the economy, he said. And even as NASA experiences budget cuts, the extraordinary wealthy are willing to pay small fortunes to go into space or into the depths of the ocean, said the public policy professor.
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