Yes, if you are a U.S. citizen, you can technically take a cruise to The Bahamas without a passport, provided it is a "Closed-Loop" cruise. This means the voyage must begin and end at the same U.S. port (e.g., Miami to The Bahamas and back to Miami). Under the Western Hemisphere Travel Initiative (WHTI), you can use a government-issued photo ID (like a driver's license) paired with an original or certified copy of your birth certificate. However, this is strongly discouraged by both the U.S. State Department and cruise lines. If you were to miss the ship in Nassau or have a medical emergency requiring you to fly back to the U.S., you cannot board an international flight without a valid passport book. Furthermore, some private islands or specific Bahamian excursions may have their own stricter requirements. To ensure a "hassle-free" 2026 vacation and protect against unforeseen travel disruptions, carrying a passport book remains the gold standard for any international maritime journey.