“In addition to motoryachts and sailing yachts, I believe that submersible superyachts will be an additional and appealing third category of private vessels,” reveals Christian Gumpold, the CEO of Migaloo PSY (Private Submersible Yachts), the Austrian design company behind this 166-metre, 2 billion USD submarine named M5. Suitable of cruising in both tropical and arctic conditions, it can dive down to depths of 250 metres and stay below the surface for up to four weeks at a time. The range is substantial too, at 8,000 nautical miles, and it can reach 20 knots when surfaced and 12 when submerged.

As conceived, the M5 will cost 2 billion USD to build, accommodating 14 guests, 32 crew, and boasting a 220-sqm owner’s suite, two observatories with floor-to-ceiling glass windows, a 200-sqm spa, one indoor and one outdoor cinema, a pressurised hangar that allows you to stow a helicopter before descending, and two mini-subs for further deep-sea exploration.