SOUTH CHINA SEA (Dec. 29, 2020) Cryptologic Technician (Collection) 3rd Class Jamekia Nelson, left, from Cleveland, assembles an M9 service pistol as Cryptologic Technician (Maintenance) 2nd Class Jalen Pontious, from Los Angeles, assembles an M500 shotgun during a weapons familiarization training in the ship's classroom as part of the Navy Security Force Sentry (NSFS) course aboard the Arleigh Burke-class guided-missile destroyer USS John S. McCain (DDG 56). McCain is assigned to Destroyer Squadron Fifteen (DESRON 15), the Navy's largest forward-deployed DESRON and the U.S. 7th Fleet's principal surface force. (U.S. Navy photo by Mass Communication Specialist 2nd Class Markus Castaneda)