If you’re traveling by land or sea to Canada, Mexico, Bermuda, and the Caribbean, you can bring a U.S. passport card instead of a passport book. However, a passport card does not work for air travel into Canada, Mexico, Bermuda, or the Caribbean.
There are some advantages to traveling with a passport card rather than a passport book, mainly cost and portability. Currently, a passport card costs only $65 to issue, while issuing a passport book is $145. For adults, both are valid for 10 years before you need to renew them. For children under 16, both are valid for 5 years.
Another benefit of a passport card is its smaller size. A passport book is 5” x 3.5” when closed and contains several pages, while a passport card can easily fit into a wallet, money belt, or pocket. (Just make sure it’s a secure pocket with a zipper so it doesn’t fall out.)
That being said, we always recommend bringing a valid passport book on your cruise. If you don’t make it back to your cruise ship on time after visiting a port, or if a family emergency requires you to fly back home from one of your cruise destinations, a passport card won’t allow you to travel on a plane. In case there are any unforeseen inconveniences, a passport book will always work as a valid travel document via air, land, and sea.