(CNN) -London, England -- Virgin mogul Richard Branson recently unveiled a new ocean plaything for the intrepid super rich: A deep-sea submarine.
"Necker Nymph," an "underwater plane" that can dive up to 40 meters below the surface, is the latest addition to to Branson's luxury collection which includes a private island, a superyacht and a spaceship.
For those wealthy enough to indulge, the experience aboard the submarine, which is nimble enough to perform "dolphin-like flips," will be like "flying underwater," said Branson's Virgin Limited Edition division.
But even for those with deep enough pockets, it doesn't come cheap: $25,000 for a week's charter and another $88,000 for the sub's superyacht launch vessel, "Necker Belle."
The $631,000 flying sub, the first of its kind, uses fighter jet technology and was designed by Hawkes Ocean Technologies. It is transparent enough to allow divers a 360-degree view of marine life and Virgin is marketing it as a way to view dolphins and whales close up.
The new sub also appears to be environmentally friendly. It is buoyant, which stops it from mistakenly landing on reefs, and it is relatively quiet -- allowing it to pass through fragile ecosystems without causing too much upheaval, Virgin says.
Potential deep-sea divers must take half-day safety courses beforehand and can then dive for up to two hours at a time.
The submarine will be delivered to Necker Island, Branson's private Caribbean hideaway, later this month.
"Necker Nymph" is not Branson's first foray onto the frontlines of adventure technology.
Last December, he unveiled "SpaceShipTwo," a spacecraft that promises to take civilians into orbit for a cool $200,000 by 2011.
