Many people wonder what the difference is between a passport card and a passport book.  A passport card was created for the sole purpose of making it easier to DRIVE from the United States to Mexico or Canada.  The only document acceptable for FLYING between any country is a passport book. 

Most cruise lines do not require a passport at all if the cruise starts and ends in the same port in the United States HOWEVER, if you miss the ship, have a death in the family, have a medical emergency, or miss the ship in a port you will need a passport book to fly home or to the next port.

Also if you have purchased travel insurance and do NOT have a valid passport book and need to fly home or to another port they will NOT cover the costs. 

Check out the following website:

http://travel.state.gov/travel/cis_pa_tw/cis_pa_tw_2223.html”