Ultimate Vacation Home Aboard World's Largest Private Yacht

Call it creative housing: It's a condominium at sea for the uber-wealthy. The World, which is a 644-foot ship with 165 apartment units, roams the seas visiting exotic ports 365 days a year. It has restaurants, nightclubs, shops and theaters on board -- even a putting green. For most of its residents, it's a second (or third) home. A few live on it full-time.

Are you having a "drop me in that briar patch" moment?

Mira and Jayson Calton certainly did. She sold her New York public relations business and he his Florida chain of spas and gyms, they got married -- on board of course -- and the couple (pictured at left) began what's been a six-year journey of both personal and professional discovery. What better place to start a new life -- or the next chapter of your existing one -- than on the high seas, Mira asks?

In the Caltons' case, they spend 10 months a year living on the ship and have traveled to more than 100 countries on seven continents. They will be publishing a book, "The Naked Calories," in January based on their travel observations of how native dietary patterns and lifestyle choices affected the development of modern disease. From camel treks through the Sahara, to visit troglodyte dwellings in Tunisia, to five-hour canoe rides deep into the Amazon jungle, to study the remote tribes surviving there, the Caltons say that they have ventured farther and longer than they could have ever imagined doing if The World wasn't there waiting for them in port.

The Caltons rent out their studio unit when it's not in use.

For the time being, The World has cornered the market on residential cruise ships -- if not on the concept, at least in the execution. And for the record, they'd prefer we didn't call it a cruise ship. Its PR folks say it's the world's largest privately owned yacht. Residents come from around the globe, and most tend to be industry leaders and political dignitaries. Who they are is kept out of the public limelight by design. But what they paid, well that's less of a secret. A lot -- and with no mortgaging available, sales are all-cash. Prices range from $750,000 for a studio apartment to $10 million for the one-of-a-kind six-bedroom penthouse. There is also an equivalent of an HOA fee paid monthly, which includes the costs of maintenance and facility use.