The passport requirement for Ocean Cay MSC Marine Reserve (MSC's private island in the Bahamas) depends entirely on your citizenship and the nature of your cruise. If you are a U.S. citizen on a "Closed-Loop" cruise—one that begins and ends at the same U.S. port (like Miami or Port Canaveral)—you are technically permitted to travel with just a State-issued birth certificate and a government photo ID (like a driver's license). However, MSC and all major cruise lines "strongly recommend" a valid passport. This is because the private island is located in a foreign country (The Bahamas). If you were to have a medical emergency or miss the ship while on Ocean Cay, you would be unable to fly back to the U.S. or enter the Bahamas officially without a passport. For non-U.S. citizens, a valid passport and potentially a visa (depending on your nationality) are mandatory for the cruise, and by extension, for going ashore at the private island. Always check the specific 2026 travel advisories, as "Passport Cards" are also an acceptable alternative for sea travel but not for international air travel.