| Unless things have changed in the last year, and I don't think they have, you don't need any type of passport to get on and off the ship -- just your Key to the World card and photo ID. (Now, we've never disembarked at Nassau, so I can't be positive about this, but we definitely didn't need passports to disembark at Castaway Cay, which is also the Bahamas, or any of the other ports.) I carried photocopies of my family's passports "just in case," but a passport card would probably provide the same security.
Happy planning,
Melissa
__________________ | Planning a Disney Wonder 4-night cruise, January 2010 | |