Want to hop all over the map without ever having to repack?Embark on a world cruise. Jeff Wise finds out what it's really like to go around the world in 80 days (or more)

The Florida sunshine streams across the teak-planked balcony outside the living room as Mary and Laszlo Rendas—surrounded by a small cadre of valises and garment cases—settle into their new quarters. For the next 105 days, the 362-square-foot Verandah Suite will be their floating home-away-from-home, as Holland America's Prinsendam sails through its annual world cruise to South America, Africa, India, and the Mediterranean. For Mary and Laszlo, it will be an epic adventure, but not a novel one: they've taken the same type of trip every year for the past 22 years. "We're hooked!" Mary says.

They're not alone. Though around-the-world cruises are the most lavish trips marketed by the travel industry, running up to $500,000 per couple, the cruise lines can barely keep up with requests for them. Fifteen years ago, only one company offered world itineraries; today, four do. And by 2007, total capacity will nearly double, as Cunard adds the Queen Mary 2 to its world-cruising fleet, Holland America shifts its circumnavigating cruise to a larger ship, and Silversea jumps on the bandwagon with its 382-passenger Silver Shadow. Even so, demand is sufficiently brisk that top-end cabins for these sailings are in short supply. "We're already booking cruises that depart more than a year from now," says Eric Maryanov, owner of All-Travel, an agency in Los Angeles. "And we can't always confirm the cabin that a client wants."

This heyday of the ultra-long cruise has been fertilized by an extravagance of two essential factors: free time and disposable cash. "The oldest boomers are turning 60," says Andrew Poulton, Regent Seven Seas' director of marketing. "They're getting to that phase of their life where they have more time and money." They've matured in an age of increasing international sophistication and curiosity, but they're not at a time in their lives when they're looking to endure great physical rigors in their pursuit of new experiences.

Aging boomers aren't the only customers, though. "More than 25 percent of our guests taking world cruises are under 60, and the number is increasing," says Mimi Weisband, a vice president of Crystal Cruises. That's good news for the cruise lines, because once a passenger ascends to the ranks of world cruisers, he tends to stay there—Holland America reports that 50 percent of its world cruisers are repeat customers. The global voyage appeals to those who want to see a lot of the world with a minimum of effort. Passengers can pack in a huge range of destinations in a single trip, with far fewer hassles and for much less money than if they had to negotiate an endless string of airlines, hotels, and restaurants on their own. The experience is almost infinitely customizable, with cruises offering a smorgasbord of shipboard programs and land excursions. And anyone hankering for a more autonomous experience can simply get off, explore independently for a few days, and then rejoin the ship at its next port of call. In fact, that's encouraged.

Nomenclature notwithstanding, world cruises don't necessarily go all the way around the world. The route the Rendases will follow on the 105-day "Circle of the Sun" itinerary aboard the Prinsendam, for example, will turn left at India, taking them home via the Mediterranean instead of eastward via the Pacific. (Trips can also be broken into shorter segments and purchased individually.) Whatever their specific itinerary, however, they tend to follow certain parameters: They always leave in the first half of January, to take advantage of the most favorable weather in both the Northern and Southern Hemispheres. They cross the equator at least twice and usually cover more than 30,000 miles and 30 to 45 ports in between. As a rule, the ships are among the most lavish of a company's fleet and command the highest level of service and amenities. And the journeys are all very, very long, lasting from 80 to 126 days.

Thanks to this luxury of time, a world cruise takes on a rhythm different from that of a shorter voyage. The ship spends more days at sea, making long blue-water passages of up to a week in length. "On shorter cruises, everyone's trying to drain every moment. People are rah-rah," says Barbara Burr, a cruise enthusiast who runs a Long Island real estate and construction business with her husband, Carl. "On a world voyage, you go at a slower pace. You have more time to enjoy things." And because they're in a relatively safe environment, surrounded by the same roster of friends and well-known staff members, many passengers feel free to indulge in a more glamorous version of their usual selves. Women bring furs, evening gowns, and jewelry normally consigned to safe-deposit boxes. Some couples, reportedly, bring so much stuff that they book a second cabin just to store it all.

On a day-to-day basis, though, living aboard a world-cruising ship is getting more and more like living ashore. "It's a change in mind-set," Maryanov says. "You're not out of communication or missing life's major events just because you're on a cruise." That's making the whole business a lot more attractive for the burgeoning number of younger, working-age passengers, many of whom still need to keep in touch with projects back home. "We have a family business, investing in and managing real estate," says Dianne Schoolfield, a 59-year-old Florida real estate investor who sailed aboard Crystal this year with her husband, Wayne, 64. "We had our laptop computer and a printer with us. We were able to stay in touch with the office almost every day." Plenty of world passengers are like Schoolfield, using the ship as a second home. "It's a lifestyle purchase," Maryanov explains. "Instead of spending the winter in Florida, they winter on board a cruise ship. They come back each season to the crew and the friends that they met during previous trips. That's why there's a loyalty."

Even devout world cruisers like a little variety, so the plotting of itineraries is designed to take advantage of special events. The Prinsendam timed its arrival off the coast of Turkey this past spring to coincide with a total solar eclipse. During next year's sailing, Crystal Serenity will stop in Rio during Carnival. The sailing route, too, has to be more interesting. Next year, Regent Seven Seas' Mariner will make a first-ever stop at Maputo, in Mozambique; next year, Silversea will make maiden calls at Pitcairn Island, Robinson Crusoe Island, and Easter Island. Upon reaching these distant ports, the ships may stay for several days, to let guests explore in depth, or even arrange land-based overnight excursions. On Crystal's 2006 world cruise, passengers took side trips to explore Uluru, Victoria Falls, and the Ngorongoro Crater, among other places.

Although it may seem to some that embarking on a lengthy cruise is too much of a good thing—a means to checking off different destinations like options on a luxury car—consuming travel on this scale somehow still feels more, well, fulfilling than accumulating wine bottles or stuffing new acquisitions into a four-car garage.

Back aboard the Prinsendam, Mary Rendas is finishing up her unpacking and getting ready to track down all the friends she hasn't seen in the past eight months. "We've become like a close-knit family," she says. "It's wonderful to see everyone, and catch up on news, and relive old memories. It's like a homecoming."

Jeff Wise is a T+L contributing editor.

Crystal Cruises

Crystal Serenity
Miami to London, 109 nights, departs January 20.
800/804-1500; www.crystalcruises.com; from $47,290 per person, double.


Queen Elizabeth 2
Round-trip from New York, 108 nights, departs January 8.
800/728-6273; www.cunard.com; from $19,682 per person, double.

Queen mary 2
Round-trip from Fort Lauderdale, 80 nights, departs January 10.
from $26,050 per person, double.

Holland America

Round-trip from Fort Lauderdale, 105 nights, departs January 15.
800/426-0327; www.hollandamerica.com; from $18,799 per person, double.

Regent Seven Seas Cruises

Seven Seas Voyager
Round-trip from Fort Lauderdale, 111 nights, departs January 9.
877/505-5370; www.rssc.com/worldcruise; from $89,070 per person, double.

Silversea Cruises

Silver Shadow
Fort Lauderdale to New York City, 126 nights, departs January 15.
877/760-9052; www.silversea.com; from $56,884 per person, double.