Do you need a passport? The Passport requirement for American passengers on cruises to Bermuda is that US citizens must present either a passport book or card when returning from Bermuda.
"Closed-Loop" Cruises: If you are a U.S. citizen, and you board a cruise ship at a U.S. port, travel only within the Western Hemisphere, and return to the same U.S. port on the same ship, you may present government-issued photo identification, along with proof of citizenship (an original or certified copy of your birth certificate, a Consular report of Birth Abroad, or a Certificate of Naturalization). Please be aware that you may still be required to present a passport to enter the foreign countries your cruise ship is visiting. Check with your cruise line to ensure you have the appropriate documents.
U.S. citizen children under age 16 arriving by sea from Bermuda may present an original or certified copy of his or her birth certificate, Consular Report of Birth Abroad, or Certificate of Citizenship.
The above information is subject to change at any time by the fine folk running the government. Go to the US Department of State website for current information about passports and how to get one.