It's the ultimate billionaire toy: A 377-foot yacht with a swimming pool that doubles as a submarine.

The six-deck yacht-submarine hybrid, named "Migaloo" after an albino humpback whale, has not actually been built.

The contraption was created to satisfy the demand of adventurous billionaires who want a truly unique boat, according to Austrian industrial design studio motion code: blue,

With a 26-foot pool, cinema room, helipad, library, gym, laundry room, and private lounges, Migaloo would be perfectly equipped for the discerning billionaire.

Plans call for it to be constructed with special pressure-proof glass and underwater lights to offer spectacular views when the submarine dives.

No word on the cost yet, but given that this will be highly customizable, expect it to be in the multi-million dollar range.