It has been billed as ‘the most extraordinary yacht ever built’.
A 390ft (118.8m) vessel – rumoured to be owned by billionaire Bill Gates – boasts a basketball court, beach club–style infinity pool, 15 cabins, a landing area for helicopters and even a private hospital.
The ship, named ‘Breakthrough’, also features multiple libraries, a cinema, several hot tubs and has been hailed as the first hydrogen–powered ‘net zero’ superyacht.
The ultra–luxury boat is about to go up for sale for the first time, at the Monaco Yacht Show in September.
But its extravagance demands a hefty price tag of $645million (£476million).
The elusive vessel, which took five years to design and build, will be the largest yacht attending the show.
It has the capacity to host 30 guests in 15 cabins, who will be looked after by up to 43 crew members.
The owner’s on–board accommodation, however, extends to a ‘completely private’ four–story townhouse tucked away inside the yacht.

The vessel boasts a basketball court, beach club–style infinity pool, 15 cabins, a landing area for helicopters and even a private hospital

Two impressive staircases lead to a seating area at the back of the 30ft–long boat, billed as ‘the most extraordinary yacht ever built’

An infinity pool provides a ‘beach club’ vibe, with large white sunbeds to complete the ultra–luxury look
Yacht dealer Edmiston, which appears to be brokering the sale of the ship, said the owner’s deck was ‘designed for family use’ and is essentially an apartment with two bedrooms, twin bathrooms and dressing rooms, a gym, a pantry, two offices each with a fireplace and a living room.
It adds that the private living quarters ‘includes both a spacious staircase lined with bookshelves and displays nooks and an owner’s elevator’.
‘At each deck level, there are inviting private lifestyle destinations to savour such as a coffee corner and games niche on the bridge deck, a library on the main deck, and a private dining room with a sea terrace and adjacent ensuite stateroom on the lower deck,’ the dealer said.
‘It creates, in essence, a secluded four–level townhouse–by–the sea within the much larger yacht.’
In total there are five decks above the waterline and two below, with the owner’s deck 121ft (37m) above water.
There are also 14 balconies that are ‘unnoticeable when closed but slide out at the touch of a button, carrying with them their side railings or walls’.
The website reads: ‘When fully deployed, their floors rise to become perfectly level with the interior room.’
A mix of textured fabrics, leathers, marble, rattan and limed oak make up the interior, creating a ‘luxe coastal vibe’.

A large seating area provides wide views, along with an enormous jacuzzi that’s warmed using heat generated from processing pure hydrogen

Chief executive Jamie Edmiston said the yacht will be ‘the one that will change it all’ due to is being solely powered by liquid hydrogen and a next–generation fuel cell system

A mix of textured fabrics, leathers, marble, rattan and limed oak make up the interior, creating a ‘luxe coastal vibe’

Bill Gates, 69, reportedly commissioned the world’s first hydrogen gas fuel-cell superyacht, built by Dutch shipbuilder Feaship, in 2021
Chief executive Jamie Edmiston said the yacht will be ‘the one that will change it all’ due to it being solely powered by liquid hydrogen and a next–generation fuel cell system.
Hydrogen fuel cells have been used to power both rockets and cars, but so far nothing has existed in the maritime sector.
The compressed liquid hydrogen is stored below deck at –253°C, and the heat generated during processing is then used to warm the likes of the pool and steam room, as well as the towel bars and flooring in the guest bedrooms.
For longer journeys, or when pure hydrogen is not available, the electricity powering the ship comes from a second–generation biofuel that ‘reduces harmful emissions by 90 per cent’.
‘The brief was to build the greenest and most environmentally advanced yacht ever built, without compromise,’ Mr Edmiston said.
‘It was a huge challenge, but one that the team has embraced and delivered on.
‘The yacht we see today, designed by RWD and built by Feadship, is without doubt the best yacht ever built.’
Jan–Bart Verkuyl, director of Feadship, said fuel cells will play an important role for yachts in the years to come due to their ‘superior efficiency, low particle emissions and low noise radiation’.

The superyacht has the capacity to host 30 guests in 15 cabins, who will be looked after by up to 43 crew

The ultra–luxury ship is about to go up for sale for the first time, at the Monaco Yacht Show in September
Earlier this year it emerged that Microsoft founder Bill gates has never set foot on the multimillion–dollar superyacht.
Despite the glamorous and high–tech nature of this boat, Gates has never once enjoyed its amenities – or even gone onboard, Luxury Launches reported.
Although has Gates never officially confirmed his connection to Breakthrough, also known as Project 821, it has been widely understood and reported on that he was behind the undertaking.
It has previously been reported that Canadian billionaire Patrick Dovigi, CEO of Green For Life Environmental, is allegedly set to buy the yacht.