Billionaire entrepreneur Sir Richard Branson is currently building a $670,000 "underwater plane" called the Necker Nymph capable of diving to 130ft. The Nymph uses fighter jet-like carbon fiber wings to "fly" in the sea. Branson hopes to one day develop a submersible that can travel 35,000ft below the surface of the ocean -- deeper than Mount Everest is tall. More at The Telegraph.