The Ultramarinum Marine watch, made by Swiss company Horus, promises to give its owners "the power of time". By pressing a button, the company promises, "the owner can play with the seconds, minutes and hours and make them follow the pace of his or her choice, then return to current time at any point."
The idea is that millionaires can enjoy the illusion of being in a slower or faster world, by making their watch faster or slower. If they are sunbathing and want to pretend the world has stopped moving, they can even stop the time. When they need to return to the real world – or find out the correct time – they push a button and the watch returns to normal.
Gadget experts are amused if a little bit confused by the watch, whose design has been inspired by the 1920s steam yacht SS Delphine.
Kat Hannaford, the contributing editor of Gizmodo, said: "This is clearly aimed at yachtsmen. But there are few places where accurate time is more important than when you are at sea and you need to know the time of the tides and the setting of the sun.
"And I am guessing anyone who has £400,000 to spend on watch is probably glued to their Blackberry all day anyway. The watch is going to appeal to owners of super yachts that never leave their moorings in the Monte Carlo harbour, rather than true sailors."
The watch face is made of teak, titanium and the mechanism inside the watch includes 45 rubies. It is water resistant to 100 meters and shockproof. The strap is made of canvas and leather.
The speeding up and slowing down mechanism is controlled by "a marine tourbillion function".
The founder of Horus, Andre Grossmann, who designed the £410,000 luxury item, defended a watch that didn't tell the correct time.
He said: "It took four years to create this breathtaking time-piece. We used avant-garde materials and revolutionary technologies to create a watch with a time-control system. I am really pleased to be able to offer people the possibility of controlling time. That, for me, is the very essence of true luxury. What could be more precious than time?"
Anyone won over by the Ultramarinum Marine watch can buy it from one of Horus's three shops situated in Montreux Switzerland, Monaco and Abu Dhabi.