Love chocolate? Imagine sailing to the Caribbean while sipping chocolate drinks, devouring chocolate desserts and listening to pastry chefs espouse the emotional and health benefits that come from eating chocolate.

You're not in some kind of chocolate delirium. Radisson Seven Seas Cruises offers a "Chocolates in Paradise" voyage in December -- one week of indulgence that will have you throwing your diet overboard.

Or how about a cruise for bikers? In November, motorcycle enthusiasts can board Royal Caribbean's Voyager for its "Hogs on the High Seas" trip to the Caribbean -- seven days of best-beard contests, prize giveaways and custom motorcycles on display.

Themed cruises, popular more than a decade ago before fading from most cruise lines' itineraries, are making a comeback. Many lines are offering sailings this fall and winter ranging from kosher cruises for Jewish holidays to private concerts with '70s rock stars and treasure hunts with the crew of the BBC's version of "Antiques Roadshow."

"There are so many different specialty themes that have appeal," said Jennifer De La Cruz, a spokeswoman for Carnival Cruise Lines. "We don't do a lot of them, but they do present an interesting marketing opportunity, and they're quite enticing to individuals that have an interest in those subjects.

"Where else can you rub elbows with Kevin Cronin and see groups that you loved in your youth?"

Cronin, the front man for REO Speedwagon, will be sailing with his band mates on Carnival's "Rock 'n' Roll Holiday Cruise" to the Caribbean in November. Members of Styx and Journey will join them for concerts and question-and-answer sessions.

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