In most cases, yes, even for closed-loop cruises that start and end in the same U.S. port. While some exceptions exist, it's generally recommended to have a passport for any cruise, as it simplifies the embarkation and disembarkation process, allows for spontaneous shore excursions, and provides peace of mind in case of unexpected events.

The basic requirements are a completed application form, proof of U.S. citizenship (birth certificate or naturalization certificate), a recent passport photo, and a government-issued ID. Additional documents may be required depending on your circumstances.

Having a passport offers several advantages, even on domestic cruises:

• Medical emergencies: If you require medical attention ashore and need to be airlifted to another country for treatment, your passport will be necessary for identification and immigration purposes.

• Missed embarkation: If you miss your ship's departure due to unforeseen circumstances, having your passport will allow you to fly to the next port of call and rejoin the cruise.

• Unscheduled port changes: If the cruise itinerary changes due to weather or other factors, and you disembark in a different country, your passport will be required for immigration clearance.

• Lost or stolen travel documents: If your passport is lost or stolen while ashore, having a photocopy or digital scan can help expedite the replacement process.

Remember: Even if you don't need a passport for your specific cruise, it's a valuable travel document that can provide peace of mind and flexibility during your trip.

Processing times can vary, but it's generally recommended to apply at least 4-6 months before your travel date to ensure you receive it in time. Expedited processing options are available for an additional fee.