The world's first hydrogen-powered superyacht, known as Project 821, has been launched by the Feadship yard Royal Van Lent in the Netherlands. This 390ft megayacht utilizes electro-chemical fuel cells to convert 'green hydrogen' into electrical energy, with water being the only by-product. The yacht features a compact battery bank, electric thrusters, and a cryogenic fuel tank to store the hydrogen at a temperature of -253°C. Despite the complexities of hydrogen storage, the yacht offers a range of 6,500nm at a maximum speed of 17 knots. In addition to running on hydrogen, the yacht can switch to a more conventional diesel-electric mode using MTU generators for added autonomy especially in regions where hydrogen supply might be limited. With accommodation for 30 guests and 44 crew members, the yacht boasts luxurious amenities like a contraflow pool, cinema, and a mini hospital. The innovative design of Project 821 showcases the potential for hydrogen as a sustainable power source in the marine industry and sets a new standard for future technology in luxury boating. Although the price of the yacht is undisclosed, it is estimated to exceed half-a-billion euros, reflecting the exclusivity and advanced technology incorporated into this groundbreaking vessel.