The Good Life.

Byline: José Pacas (Alex McRae Kris Anderson Karla Bruning)

Travel: Staying at Sea

By Karla Bruning

Forget sailing around the world in 80 days. Try 126. That's how long Silversea's first luxury circle-around-the-earth cruise takes. And it is not the only new marathon cruise out there; for 2007, luxury liners are offering up an assortment of lengthy new itineraries with shore excursions in plenty of remote as well as urbane locales. "There is a new market out there," says Joe Proto, Silversea

Cruises' director of world cruise and business development, citing a mix of empty nesters and entrepreneurs among those seeking an ultraluxurious--and ultralong--holiday at sea.

Silversea's "World Cruise 2007" is the longest on the market. Travelers spend more than a third of the year aboard the all-suite vessel, docking at 61 ports on six continents. Among the 200 shore excursions and 22 overland treks: breakfast at the Royal Stables in Dubai, stays at exclusive spas in Asia and a "Lord of the Rings" tour in New Zealand. "The response has been phenomenal," says Proto ($52,794; silversea.com ).

Crystal Cruises is offering the 109-day "Treasures of Sun & Sea" voyage, which visits 44 ports on five continents. Side trips include a wildlife expedition in Antarctica, a cruise down the Amazon River and a hike up the glaciers of Patagonia. Extended offerings in Africa promise maiden calls to Tunisia and Mozambique, along with a wide range of overland safaris ($47,290; crystalcruises.com ).