180805-N-TW634-169 PACIFIC OCEAN (Aug. 5, 2018) The transfer skirt hatch of the pressurized rescue module (PRM) of Undersea Rescue Command (URC) opens after mating with the Chilean Submarine (CS) Simpson (SS 21) on the ocean floor during the submarine rescue exercise CHILEMAR VIII. CHILEMAR VIII is a bilateral exercise designed to demonstrate interoperability between the U.S. submarine rescue systems and Chilean submarines. (U.S. Navy photo by Mass Communication Specialist 2nd Class Derek Harkins/Released)