Commissioned by eco-conscious Bill Gates, the brand-new 390-foot (118m) Breakthrough is the world's first hydrogen-powered superyacht. Designed by RWD and built by Feadship, the revolutionary vessel showcases futuristic green technology for emissions-free cruising.

Brimming with top-end amenities, Breakthrough sets a new benchmark for sustainable nautical luxury. Yet for whatever reason, Gates has decided to sell. A rumour that Patrick Dovigi had acquired the yacht as a replacement for Lady Jorgia/Ahpo has been debunked by SuperYachtFan, and Breakthrough remains on the market.

Available through Edmiston, the asking price is on application, but it's speculated to be as high as $675 million (£469m). This would make Breakthrough the priciest superyacht on sale right now by a very wide margin.

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