Having experienced two previous tours of lifeguarding, Trepangs men otherwise expected a series of long dull days, spent moving in circles, squares, or triangles to break the monotony. However, shortly before 12:00 on 24 June 1945, her first day of lifeguard duty, lookouts spotted a blossoming parachute overhead and soon saw the splash of a crashed P-51 Mustang fighter damaged while escorting Superfortresses to Tokyo. Trepang bent on full power and soon picked up the downed aviator, Second Lieutenant Lamar Christian, USAAF, safe and sound. During the maneuver, another Mustang, piloted by First Lieutenant Frank Ayres, USAAF, radioed that it, too, was in trouble; and the pilot requested permission to bail out. Trepang replied telling Ayres to "be patient" until the first rescue was complete. Ayres circled the submarine until Christian was safely on board the submarine. Ayres then executed a perfect jump and landed some away from Trepang and was soon hauled on board.
