The outer defense line includes the physical security measures taken by the security division and the cruise lines before passengers and crew go on board. The inner defense line involves the security measures taken inside a cruise ship after the passengers and crew are already on board. The development of the outer defense line was preceded by a security site survey and a threat assessment analysis. A liaison structure between Federal, State, and local personnel who would respond to a terrorist attack has been developed. Electronic systems have been installed to monitor access points, and means for checking passengers and their luggage have been instituted. Security officers and other terminal personnel have been trained in terrorism security measures and responses. For the inner defense line, all cruise ships have designated a ship security officer, who is responsible for the implementation and maintenance of the ship security plan. A comprehensive training program for crew members is designed to acquaint them with security measures and heighten their awareness of the terrorist threat.