As with any island cruises, on these you can snorkel, have an open-air massage, and partake of bountiful food and drink amid swaying palms and powdery white sands. But what makes these cruises different is that they take you to islands available only to ship passengers. (Prices current as of mid-December, 2011.)
1. Castaway Cay
Disney Cruise Line purchased this 1,000-acre Bahamian island, part of the Abacos chain, in 1984, and it's become the line's top-rated port of call. It's so perfectly configured for beach fun that you might think a dose of pixie dust was involved in its creation. There's an expansive beach for families, a separate one for teens and a quieter swatch for adults. Wet fun includes a floating play area, Pelican Plunge, decorated in faux flotsam and jetsam and equipped with waterslides and water cannons. Three-night cruises on the Dream from Port Canaveral, Fla., start at $880.
2. Half Moon Cay
Nature is what sets island cruises to this retreat apart. Holland America Line maintains a two-mile crescent-shape beach for its passengers, as well as for passengers on Carnival Cruise Lines ships. The rest of the island, formerly known as Little San Salvador, is a bird sanctuary operated by the Bahamian National Trust. Try to roll out of your beach hammock to hike, horseback ride or bike the network of bird-watching trails. Seven-day cruises on Holland's Eurodam, departing from Fort Lauderdale, start at $550; out of Miami, a five-day sail on Carnival's Destiny is $700.
3. Great Stirrup Cay
Norwegian Cruise Line passengers can play Gilligan on the northernmost island in the Bahamian Berry chain. Norwegian purchased this former World War II military outpost back in 1977. Attractions include a 1963 lighthouse, a pirate-tale-filled history and fun in the sun — including whizzing down an inflatable slide. Three- and four-day sails out of Miami on the Sky start at $200 and $250, respectively. (AARP members can book with Norwegian, an AARP-approved provider, through the AARP Travel Center powered by Expedia.)
4. Coco Cay
This private Bahamian island, formerly known as Little Stirrup Cay, is tiny at only 140 acres. But Royal Caribbean makes the most of the space. Activities include snorkeling around a replica of a Blackbeard ship and WaveRunner tours. There are also nature trails to explore and a re-created Bahamian village in which to shop. You're spoiled for choice of vessels and trips: from three nights out of Port Canaveral on the Monarch of the Seas (starting at $180) to nine nights out of Baltimore on the Enchantment of the Seas ($710).
5. Taha'a/Motu Mahana
The most remote of the island cruises takes you to a gorgeous islet in French Polynesia. Thanks to Paul Gauguin Cruises, you can play South Seas castaway in style — complete with drinks served in coconuts and strolling beach musicians. Luxury is costly, though. A six-night sail out of Papeete, Tahiti, aboard the Paul Gauguin starts at $9,000. That said, this line sometimes has promotions that cut fares in half.
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