A
390ft superyacht, reportedly owned by billionaire Bill Gates, is up for sale with a staggering $US645 million price tag. Although Gates has never publicly confirmed his involvement, the vessel's design and features suggest it was built to his specifications.

    The yacht, named "Breakthrough" or "Project 821", took five years to complete at Dutch shipyard Feadship and boasts seven decks. Its unique feature is a next-generation hydrogen fuel cell platform that allows it to operate entirely off compressed liquid hydrogen, reducing emissions by 90% when biofuel is used.

    The interior is designed to evoke a coastal resort aesthetic, with a blend of luxurious materials such as leathers, marble, limed oak, and rattan. The yacht features an impressive array of amenities, including a full-size basketball court, cinema, several hot tubs, and a private hospital.

    The owner's quarters span four private floors, complete with two bedrooms, twin bathrooms, dressing rooms, offices, a gym, pantry, and living room. Discreet balconies slide out from the hull at the touch of a button, providing private lifestyle destinations at each deck level.

    With its cutting-edge green technology and opulent amenities, Breakthrough is set to be the largest yacht on display at the show. The listing is being handled by yacht brokerage Edmiston, with CEO Jamie Edmiston calling it "the one that will change it all."