Like its iconic palm trees, the Caribbean sways -- each island moving to its own beat, from hammock-rockingly slow to heart-pumpingly fast.

The best way to sample a whole series of regional rhythms, of course, is to hop a ship -- particularly one that makes a point of bringing the tropics back on board. Enter Princess Cruises, whose nearly 30 Caribbean itineraries are blurring the line between island life and ship life -- and happen to be on sale. Here's how to get into the groove.