Wouldn't passengers getting off for excursions have to pass through customs anyway?
I have not been on a cruise yet with an intermediate stop in the US, but my understanding was that everyone getting off a cruise ship and entering the US was cleared by CBP at each stop, whether it be just for a day excursion or their final destination.
I just asked someone who works for CBP and said that there is always someone there who can process a passenger who disembarks. Be it people discharging for an excursion or ending their trip, there is an officer that can process them.
That would seem to back up what I said - you get cleared even if just for excursions.
The one exception to the rule would be:
When we were on Pride of America in April, we saw a party of three ,with their luggage, getting off the ship on last day (in Kauai). I don't know the circumstances around it though.
Pride of America is a US flagged vessel and cruises only between US ports. Thus, people getting on and off it don't have to go through Customs or Immigration checks.
However, there would probably be an issue if disembarking (for good) at a US port without first visiting a distant foreign port - when you start putting the cruise line in danger of fines due to breaking maritime laws, you might have problems.
That's right. An example would be the 7-night itineraries that depart Galveston, and stop at Key West before continuing to
Castaway Cay and Nassau before heading back to Galveston. It would be illegal for a passenger to disembark at Key West and end their voyage there, as that would constitute a non-US vessel providing direct passenger transportation between US ports (a violation of the Jones Act). However, crew, including entertainers, are allowed to disembark in such a situation.
If you had an itinerary that first stopped at a foreign port, and then a US port before before returning to the original US port (i.e. a "closed-loop cruise" that happens to stop at multiple US ports), you'd have another potential issue if you needed to get off at the intermediate US port: if you chose to travel only with a birth certificate because that was all that was needed for a closed-loop cruise, you'd run afoul of the rule that requires a passport for open-loop cruises between US ports. They won't deny you entry, but you could be assessed a fine.
BTW, this is a lot of the reason that the Alaska cruises start and end in Vancouver, rather than Seattle. By starting and ending in Vancouver, they can board passengers that miss the boat at any point along the way, as well as accommodate early departures from an Alaska port.
