Joe Vittoria - Mirabella VThe former CEO of Avis has the distinction of owning the largest, single-masted sloop in the world, the 247-foot-long Mirabella V. Built by VT Shipbuilding in Southampton, England, at a cost of over $50 million and completed in 2004, the 740-ton ship features rooms bathed in teak woods and light-colored fabrics. There is also an open air cinema, fitness room, on deck spa pool and three power tenders for going ashore. It's available for hire at a cost of $300,000 per week.

Larry Ellison - Rising SunAt 452 feet, this was the world's largest private yacht -- until this year, when it was edged out by 4 feet by Prince Sultan bin Abdul Aziz's recently decommissioned Saudi state vessel. Built in Lürssen, Germany, in 2004 for an estimated $377 million, the ship features 82 rooms and a basketball court. The Oracle founder has also outfitted it with everything from a landing craft that can carry an array of SUVs to bespoke mahogany tenders fashioned in New Zealand. One problem is its huge size, which makes docking at tiny ports along the Côte d'Azur, or for that matter anywhere, virtually impossible.

Paul Allen - OctopusThe world's third-largest liner is a white and blue behemoth, measuring 414 feet and thought to have cost about $254 million. It was furnished by Seattle-based designer Jonathan Quinn Barnett, who created a floating palace that includes, among other things, a movie theater, a music studio and a glass-bottomed floor where guests can gaze at the thriving sea life. While its other assets, including the presence of a half-dozen boats and a ten-man submarine, are up for conjecture, its movements are not: Octopus made its way to Durban, South Africa, and the Zanzibar Archipelago in July before passing through the Suez Canal for Malta, where it docked in late August.

Roman Abramovich - Pelorus One of four boats owned by Russian billionaire and Chelsea Football Club owner Roman Abramovich, Pelorus is a 377-foot whitewashed bullet, featuring a striking foredeck helipad, one of two on the ship. The rest of its appointments, fashioned by the Surry, U.K.-based design firm Terence Disdale, are up for debate. Some say its oversized windows are bulletproof, and as a nod to security, the vessel features a missile detection system and a crew made up exclusively of elite ex-Special Air Service soldiers. Pelorus spent most of early 2006 in Europe, visiting the Hanseatic Germany city of Lübeck, Kristiansand in Norway, and St. Jean Cap Ferrat and Capriccioli in the Mediterranean.

Rupert Murdoch - RosehertyWhen not seeing to his media empire in New York, staying at his posh loft in London or visiting the family homestead in Australia, News Corp. Chairman Rupert Murdoch enjoys time aboard his posh 183-foot Roseherty yacht. Built by Italian manufacturers Perini Navi and launched just this year, it features a hand-built grand saloon and enclosed dining area, designed by Frenchman Christian Liaigre. It was recently spotted in the Adriatic at the port of Kotor in Montenegro and north in Trieste, Italy.

Tiger Woods - PrivacyTo send a message about how seriously he guards his privacy, Tiger Woods sued Christensen Shipyards for $50 million. Why? Because in November 2004 the Vancouver, Canada-based purveyor of luxury yachts allegedly used photos of the $30 million craft to promote its handiwork in brochures. The suit was settled out of court earlier this year. So what did we learn about some of the goodies onboard? For starters, it features a top speed of 18 knots, a range of 4,000 nautical miles and an interior accented with marble and brushed stainless steel. There is also a three-person elevator, a gym and an eight-person Jacuzzi.

Leslie Wexner - LimitlessThe chairman and CEO of Limited Brands, the parent of Victoria's Secret, bought this 315-foot vessel in 1997, shortly after it was launched. He then enlisted the help of Francois Catroux, who outfitted the commodious interior of the trademark Jon Bannenberg-designed craft with 3,000 square feet of imported teak and 15 tons of marble, some of which covers the tumbledown aft section. The interior is a secret: Wexner has never permitted it to be photographed. Still, we do know that it features a unique "dolphin-cam'' that transmits live video of undersea life on the ship's flat-screen TVs. It was recently spotted docked on the island of Mallorca.

Mohammed al-Fayed - SokarIt was on this $30 million liner that Princess Diana and al-Fayed's son Dodi spent their well-documented holidays soaking up the Mediterranean sun before their deaths in Paris in 1997. Harrod's owner Mohammad al-Fayed has recently put the 16-year-old craft up for sale for $32 million. Al-Fayed is tight-lipped about his craft and very little is known about it, except that the exterior was designed by Manfredi & Sforzi and the interior, which features two indoor/outdoor dining areas and a security control room, was fashioned by Vittorio Cerruti.

Tom Perkins - Maltese FalconDespite being 289 feet in length, this $100 million mega-yacht can be sailed by just one person. That's because it's a sailing yacht: the biggest privately owned clipper yacht in the world. The vessel has two massive 1,800-horsepower engines just in case. The venture capitalist, who invested in Google and Amazon, has outfitted the craft with three masts, each of which is manufactured out of carbon fiber; the trio deploys in just under six minutes. The sleek, Bermuda-registered craft, which was just recently spotted sailing off St. Tropez, is available for charter. The cost is $450,000 per week.

Wayne Huizinga - FloridianFormally golfer Greg Norman's Aussie Rules, the 228-foot-long Oceanfast craft was sold to the Miami Dolphins and Florida Panthers owner H. Wayne Huizinga, who quickly went about refurbishing the 3-year-old yacht. Gone are the fishing rods, replaced by a helipad and extra guest quarters. Despite the multimillion-dollar renovation, Huizinga decided the swim-up bar was worth retaining. The vessel trolled the Netherlands Antilles and the Virgin Islands earlier this year before making for West Palm Beach, Fla., in June. In August, it had traveled up to Bar Harbor, Maine, en route to the Charlottetown Harbor on Prince Edward Island.