PASSPORT FOR A CRUISE Passports are required for all travellers, including citizens of U.S. and Canada, who enter or re-enter the United States by air, land or sea.
Regarding cruises to destinations in Mexico, Canada, the Caribbean, the Bahamas and Bermuda, there is a notable exception to this US passport rule, pertaining to land and sea crossings for US Citizens:
US Citizens on closed-loop cruises (cruises that begin and end in the same U.S. port) and travel to destinations in Mexico, Canada, the Caribbean, the Bahamas, and Bermuda are able to re-enter the United States with proof of citizenship other than a passport or passport card.
Source: https://www.ambassadorpassportandvisa.com. Information shared above is the personal opinion of the author and not affiliated with the website.