Virgin Group founder Richard Branson, known for such exploits as trying to balloon around the world, said yesterday he planned to explore the deepest parts of the world's oceans with a jet-like submarine.
The 5.5m vessel is capable of descents of more than 11,000m below the surface.
His project, called Virgin Oceanic, will undertake five dives over two years.
The first is set for later this year, when the team plans to explore the Pacific Ocean's Mariana Trench.
Branson plans to pilot a second dive himself, into the Puerto Rico Trench in the Atlantic Ocean.
Other areas to be explored are the Molloy Deep in the Arctic Ocean, South Sandwich Trench in the Southern Ocean and Diamantina in the Indian Ocean.
Branson said he expects the project to cost less than US$10 million ($13 million).
Branson said Virgin Oceanic could one day take passengers on deep sea dives.