The U-Boat Worx Nautilus is a 123-foot superyacht that doubles as a submersible that can travel to 650 feet below sea level. Courtesy U-Boat Worx

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At the Monaco Yacht Show, U-Boat Worx unveiled its Nautilus design, a 123-foot, 1,250-ton vessel that the company says can function as a yacht or a submersible that uses diesel-electric power down to about 650 feet below sea level.

Cruising speed is projected to be 9 knots for the Nautilus, with an underwater speed of 4 knots.

Guest spaces include a bar, pool, lounge, dining room, five guest staterooms, quarters for six crew and a galley. The entire sundeck gets retracted before the vessel goes into submersible mode. The design also includes 10 windows, each more than 13 feet wide, for views of the underwater world.

A pressure-resistant tender, the Aronnax, can be used to take as many as five divers to a scuba location away from the mothership.

According to U-Boat Worx, this “superyacht submarine” will be able to stay underwater for as long as four days. At cruise speed, it can stay underwater for six hours.

What’s the asking price to build the first Nautilus? It’s about $24.5 million. U-Boat Worx says it can deliver the Nautilus within 30 months of a contract being signed.

Take the next step: go to uboatworx.com