Originally Posted by CaptainEdwardJohnSmith
Easy answer, if you travel under a US passport, you concerns are unfounded. Your passport is in YOUR possession at all times.
I always turn in my passport to the ship. This makes it easy for all to clear immigration in each country. In some countries, our passports will be returned to us for the day if local authorities require. In other countries,we are given a "slip" of paper to show officials as we go ashore and return to the ship.
I have been amazed at the number of new stamps in my passport when I collect it at the end of a cruise. I cannot imagine having all passengers and crew to show up at each port of call to have our passports stamped if the ship had not collected the passports.