A passport is never required for sea travel within the United States. Whether you are hopping a ferry across the Potomac or cruising to Puerto Rico, all you'll need is enough money for the fare. To be safe, it's wise to carry your driver's license or another form of government ID.
U.S. travelers do not need to present passports when embarking on a closed-loop cruise, which is one that both begins and ends at U.S. ports. If your cruise to the Bahamas starts in Miami and ends in New York, you can leave your passport at home.
The Western Hemisphere Travel Initiative (WHTI), federal legislation that went into effect in June 2009, requires that all U.S. travelers leaving the country hold a valid U.S. passport. When traveling on a cruise that originates or ends in a country other than the U.S., a passport is needed.
Whether a traveler can use a U.S. passport book or U.S. passport card depends on the destination. A passport card is a cheaper, wallet-size alternative to a passport book and can be used only for land and sea travel to Canada, the Caribbean, Mexico and Bermuda.
Several WHTI-compliant documents can be presented in place of a passport book while sailing to the Caribbean, Mexico, Bermuda and Canada. Enhanced tribal cards, a Form I-872 American Indian card, an enhanced driver's license, a U.S. military ID, a U.S. Merchant Mariner's Document, trusted traveler cards and a Native American Tribal photo ID card will be accepted.
