In the old days they used to take your passport and keep it throughout the cruise so they could clear the whole ship at once. Now you get it back.
Honestly, I do not know the answer to this question, but I am guessing it is harder that it seems. You would have to find some kind of customs & border patrol in each country. Maybe someone else knows better.
I am the editor, but I also speculate, ask questions and play devil's advocate. I reserve the right to change my mind.
I remember in Cozumel, our tablemates, who always got theirs stamped in every port, had it done there...check out the official tourism bureaus of your ports.....email them, and ,if you don't see it ..and NO, not a dumb question at all
Trip, with her book & tea!
Chat Hostess & Board Moderator