(8 km) legs to maintain her station, when the ship's commanding officer noted a wake which he took to be one of the ship's own. Two minutes later, the appearance of a torpedo away on the port bow gave startling proof that the wake was that of an enemy submarine. As Tigrone swung left, the torpedo passed her abeam, less than away. She then submerged and rigged for silent running, remaining below for over two hours. On 9 April, she took up a lifeguard station off Mofu Point and continued patrols off Hainan until 15 April when she departed the area late in the day. She bombarded Pratas Reef near Pratas Island with five-inch (127 mm) gunfire on 16 April and joined submarine three days later to fire on targets including towns and docks on Batan Island. She ended her first war patrol at Guam on 24 April 1945. Second patrol After refitting by submarine tender , Tigrone departed Apra Harbor on 19 May, took on torpedoes at Saipan the same day, and on 20 May got underway for her assigned area. On 25 May, she sighted Sofu Gan Island and Tori Shima before taking up her lifeguard station south of Honshū and west of the Nanpō Islands. That same day, she rescued a downed flier from the 19th Fighter Command, Iwo Jima. Early on the morning of 27 May, Tigrone engaged a Japanese lugger which countered the submarine's five-inch (127 mm) and 40 millimeter fire with machine-gun fire. As Tigrone turned away from the raking fire of the lugger, heavy seas washed over her main deck, knocking three of the submarine's crewmen against the gun and injuring them. Despite intermittent heavy rain, Tigrone finished off the lugger with five-inch (127 mm) fire. The final and telling round caught the lugger dead center, set it afire, and stopped it dead in the water. High seas made boarding a hazardous proposition, so the battered enemy vessel was left to burn, and Tigrone returned to her lifeguard station. Early on the afternoon of 28 May, the submarine rendezvoused with a Navy bomber which had signaled its distress. The plane ditched from Tigrone, and the submarine's crew quickly rescued five survivors from the water. In the next two days, Tigrone proved her skill as a lifeguard ship as she responded to frequent calls for aid and rescued 23 men from the Philippine Sea.