We checked in and then went off the ship in Puerta Rico on the Golden Princess last May. We were gone about 3 hours and had no problem getting back on ship. You will have to go back through security at the port, but that was pretty quick too. Be sure to tell the guys taking those awful cruise pictures as passengers board that you have already been photographed and are returning to ship.
You are on the May 14 Caribbean Princess aren't you?
Have a happy cruise!!!