sentences:  The structure used as a nightclub is a signature element of Princess Cruises' ships in the "Grand" class and derived classes.The nightclub either overhangs the stern of the ship ("Grand" and "Caribbean" classes) or is located just aft of the funnel (Gem and "Crown" classes).The Gem class of ships is based primarily on the "Grand" class, but modifies the placement of the nightclub to be just aft of the funnel and also modifies the number of restaurants.