IT'S THE biggest single-masted yacht in the world - and Prince Andrew was there to admire the multi-million-pound grandeur.

The Duke of York visited Southampton yesterday to take a tour round a 75-metre superyacht being built at Woolston.

The hull Mirabella V is under construction at Vosper Thornycroft's yard in Victoria Road.

Prince Andrew wandered through the shell of the vessel, which will eventually house a 600-bottle wine cellar, luxury bedroom suites and an outdoor cinema. It will also have a garage at the stern which will store jet skis and sailing dinghies.

So large is the hull that a double-decker bus could be parked inside, with room to spare.

Mirabella V is the brainchild of American businessman Joe Vittoria, the former boss of car rental giant Avis. He plans to charter the super yacht for week-long cruises in the jetset playgrounds of the Caribbean and the Mediterranean - at $250,000 a week. Fourteen crew, including a dedicated chef, will look after 12 guests.

The Duke of York, who also went to see the 90-metre mast being built at Portchester, declined to make any public comment as he visited the site yesterday afternoon.

But project manager Mike Carter said: "The Duke was astonished at the size of the project. He was very knowledgeable."

Mirabella V, which was designed in 2001, should be launched in August and is due to be handed to its new owner before the end of the year. The 75-metre long yacht, which has a 150-tonne keel, will travel under sail at speeds topping 20 knots, and is to carry 1,400 square metres of mainsail.

It is unclear whether the Duke of York has been invited to sample life on board the luxury yacht later this year when she becomes the most sought-after vessel in the charter market.