For the billionaire who has everything, sometimes a superyacht just isn't enough -- that's why the world's wealthiest are buying "gigayachts."

These boats are the ultimate status symbol -- a sign of eminence, power and a seemingly limitless supply of cash. And when it comes to showing off wealth and status it seems the rule is "the bigger the better."

"There's definitely a 'mine is bigger than yours' syndrome in this industry and there is a desire to have the best. That's the great thing about these yachts," said Jonathan Beckett, CEO of Burgess Yachts , one of the world's leading yacht brokers.

"When you get up to 'gigayacht' status, it is all about the best and these people are used to having exceptional possessions around them all the time," Beckett continued.

Although the term "gigayacht" is not new, it is becoming increasingly prevalent as owners seek bigger and better yachts.

"There is no standard definition of what a gigayacht is," says Paul Ashton, editor of SuperYacht World

"A gigayacht I would say is anything that is over 220 feet (67 meters) where the majority of the yacht is customized and bespoke."

Their owners are part of a small but illustrious set that includes Russian oligarchs, Saudi royalty and international business tycoons.

The yacht to beat is currently Roman Abramovich's "Eclipse." The largest private yacht in the world at 163 meters long, "Eclipse" is believed to feature around 24 guest cabins, two swimming pools and a mini-submarine, and was rumored to have cost between $540 million and $1.1 billion.

Although not all gigayachts come with that pricetag, Ashton says the standard measure is around €1 million ($1.36 million) per meter of length.

"That works to a certain extent, but you also have to take into consideration which yard it is made in and the bespoke details involved," he said.

While that pricing means gigayachts are strictly for the super rich, you get a lot of bang for your bucks, Beckett explained: "There is nothing standard when it comes to this area of our market. But if you are purchasing a superyacht you would want a vessel that was transglobal and you'd want a reasonable speed.

"You'd probably want at least two helicopter platforms, so you can land your own helicopter and visitors can also land theirs, cinemas, hospitals, spas, large entertainments areas and hairdressing salons.

"These vessels have anything from 80 to 120 people onboard including the crew, so it's a little town."

But it's not all about status. The trend towards bigger yachts is due in part to new technological advances in the yachting industry as well as the changing lifestyles of gigayacht owners, says Becket.

"Going back to when I first started in the business, yachting used to be a form of camping almost," he said. "Nowadays, people are moving aboard their yachts and using them as a second home.

"Instead of going for one or two weeks, people will move onboard for the whole summer," he said.

The world's second-largest gigayacht, the "Dubai," is a perfect example of this, says Ashton. Owned by Sheikh Mohammed bin Rashid Al Maktoum, the ruler of the Emirate of Dubai and Prime Minister of the U.A.E, the "Dubai" is a working boat as well as a holiday yacht.

"There is room onboard for all of the crew, but there are also 20-30 cabins for clerical and support staff that you need when you're running your business from onboard," said Ashton.

But the financial crisis means even gigayacht owners are having to spend smarter, says Beckett.

"We've got a whole new market landscape. No one's looking to pay a strong price for a yacht, as they were pre-2008," he said. "Then it didn't matter how much you paid, it was cool to pay top price, now it matters a lot. In today's market it is cool to be paying a low price."