HONOLULU — At 9:54 a.m. Monday, a Republic of Korea Navy P-8A Poseidon roared down the runway at Joint Base Pearl Harbor-Hickam and climbed over the Pacific, heading toward its assigned patrol area. Minutes later, a U.S. Navy P-8A lifted off from Kalaeloa Airport, marking the start of another joint anti-submarine warfare mission during this year’s Rim of the Pacific Exercise (RIMPAC). For the Korean Navy, the flight carried added significance. It marked the Korean Navy’s first RIMPAC deployment of the newly introduced P-8A maritime patrol aircraft and the first time reporters were allowed to observe one of its operational missions while onboard. The exercise centered on tracking a submarine target simulator designed to replicate the movements of a real submarine. Before the patrol aircraft arrived, the U.S. Navy deployed separate simulators into the Korean and American operating sectors. Once in the water, the devices quietly followed preprogrammed routes while attempting to avoid detection. The mission for both aircraft was straightforward in concept but notoriously difficult in pra