But Carnival knows that, so they're also offering price protection. If the fare drops after you book, the cruise line will refund the difference in the form of a shipboard credit. Seems fair to me. And remember, beginning this spring, Carnival is coming to Baltimore - The Pride ship - for 6-night and 7-night sailings to the Caribbean and the Bahamas. Carnival is also offering free upgrades on virtually all of its cruises. Sounds like fun.