Specifically, you will go to a designated area (usually not the same area as those with "loyalty status" nor those with Princess excursions). When you get there you will be given an identifier (number, animal, color, etc.). When your identifier is called you will follow an escort to the water shuttle boarding area. It has been years - late 1990's at least - since we were in a scrum to get off at a port. You will wait as the shuttle is slowly filled.