The bigger, fabulously expensive, craft, are virtual floating villages, complete with advanced satellite communications systems and fully automated sail-handling with push-button winches, in-boom furling and self-tacking sails.

Some feature helipads, submarines and even missile-detection systems. All this shimmering style and hi-tech gear costs about £1million per metre for a new build - even more once you exceed the 70-metre mark. In addition, there are running costs of about £2million a year.

The world's biggest superyacht belongs to Sheikh Mohammed bin Rashid Al Maktoum. Called Dubai, it is 525ft long and was originally commissioned by the Prince of Brunei.

 

Chelsea F.C.'s Russian owner Roman Abramovich has three superyachts - Pylorus (377ft), Le Grand Bleu (370ft) and Ecstasea (282ft) - and is having the 550ft Eclipse built. When completed, it will become the world's largest.

There are now 6,000 yachts of 80ft or more on the high seas - double the number of a decade ago. The sales rush has been fuelled by the increasing number of wealthy oligarchs from the former Soviet Union and an expanding Far Eastern market.

"Yachting is very much in vogue and growing at an extraordinary rate," says Nicholas Baker, senior sales broker at Camper & Nicholsons International. "It's unlike anything we've seen before."

A super yacht takes about 400,000 man-hours to build, more than a jumbo jet,  which is why waiting lists vary between two and five years. The size of vessels is also growing. In 2002, the average luxury yacht was about 165ft in length, but this has increased to 230ft and there is a growing trend for boats exceeding 450ft.


Offsetting this major investment, chartering can generate anything from £30,000 a week for a modest vessel to £500,000 a week for a 60-metre yacht hired out for a corporate function.

When super yachts dock, their owners can take their pick from some of the most desirable places on the planet. Monaco is at the heart of the sailing world, with a glittering global social scene stretching all the way from St Tropez, Portofino and Palma, to Antigua and Newport, Rhode Island. Further afield, yachting sees enormous potential in the emerging market of China.