Sir Richard Branson plans 'underwater plane'

A £415,000 carbon-fibre winged prototype, called the Necker Nymph, is already being developed that can submerge to depths of 130ft (40m).
Sir Richard told The Sun: "It is very similar to an airplane flying in the sea. You can literally do a loop-the-loop."
But it is only the first step to his greater ambition to take one to the dark depths of the Mariana Trench in the Pacific, which is 36,000ft (11,000m) deep.
The Nymph will be moored on Sir Richard's private Caribbean island, Necker.
He said: "We hope to have submarines dotted throughout the world.