- Designer hoping to sell luxury concept
- "One in a thousand chance" of being built
- Buyers usually from Middle East, Russia
(CNN)Odds of 1,000-1 usually indicate a bet not worth taking.
But superyacht designers such as Andy Waugh are prepared to risk it as they attempt to land a dream commission.
Waugh's latest design, Epiphany, might not be the biggest -- that record belongs to the 180-meter behemoth Azzam -- but with its extravagance he is pushing the boundaries of what is possible on the high seas.
If contracted, Waugh's sleek concept would take up to five years to build. It would stretch to a comparatively modest 130 meters, but it won't come cheap.
"Cost? You're probably looking at £200 million to £500 million ($267 million to $667 million)," the British designer tells CNN. "It depends on the finish of the interior.
"If it's gold swan taps in every bathroom, then the price of the interior can be three times a more modern design. So it totally depends on the client and what they want."
Its owner will be able to enjoy an entire deck to themselves, complete with private cinema, jacuzzi, gym and spa, while guests will be able to take advantage of the same luxuries on the VIP deck below.
The chances of the yacht being built are around "one in a thousand," Waugh admits, but cost, surprisingly, isn't one of the major potential stumbling blocks.
"Lots of people like Epiphany, but what you hear a lot of the time is: 'I like this but ... I've got my own idea and I want something that is a bit more sensible,'" the London-based designer explains.
"They like stuff which is crazy, but a client needs to be able to believe -- they need to be able to see themselves on that boat -- which sometimes with the more radical designs they can't really do.
"Usually it's an inspiration, a sort of starting point for someone to get interested and they usually want something that's bespoke to them but similar to something I've done in the past."
The sort of people who can afford a $500 million boat often quickly become bored of their latest "toy," according to Waugh.
"These things basically require a high-net-worth individual to fall in love with it. Even then they tend to fall in and out of love with stuff on a whim," he says.
"I was doing a design for a Norwegian but it fell through because he couldn't sell his boat. So there are all sorts of reasons why things don't happen. Very random, really."
Clients for superyachts costing over £100 million ($133 million) tend to come from the Middle East or Russia, Waugh says, but their reason for buying can vary greatly.
Is it ego?
"Sometimes it is," he says, adding that there is competition between rich Saudis and Emiratis to have the biggest boat.
"But some guys just love yachting, they love the comfort of having a motor yacht and like to cruise around and they go to the Caribbean on it -- it's an adventure for them.
"That's one side of the market. They tend to use their yachts a lot. Then there's another side where it really is just about spending money for the sake of it and saying you've got the biggest yacht.
"Those guys might spend three weeks a year on the yacht and it's costing them tens of millions a year. A bit of an expensive toy, really."