That happened on 2 cruises so far,,I know
and its up to passenger to get to next port...I always carry passport(or copy) along with credit card,cellphone,copy of itinerary,,etc..
The first couple caught up with us in next port.The second time,,not sure WHAT happened,but never saw them again.
That s why I always either go with ships tour or realize ,,,I m on my own,,,and come prepared,,just in case.
I was NEVER something I thought about,,,until above happened and now I KNOW..