Steaming via the Canal Zone, she paused for a week of training off Panama, then set her course for Hawaii, conducting extensive practice approach exercises with attack transport Riverside en route.
After refitting by submarine tender Apollo, 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.
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.
High seas made boarding a hazardous proposition, so the battered enemy vessel was left to burn, and Tigrone returned to her lifeguard station.
On the afternoon of 24 May, Tigrone answered a call for assistance from a severely damaged PBY Catalina seaplane which had nosed into a wave on takeoff from a rescue operation.
Soon the submarine was searching again, this time for survivors of other downed aircraft who had been reported by circling planes to be floating on rafts in Tigrone’s lifeguard area.
Plagued by fog and radar malfunctions, Tigrone at last was forced to request to be assigned to lifeguard duty when a persistent loud scraping noise in the vicinity of her starboard shaft rendered normal submarine patrol and attack functions hazardous, if not impossible.
Following refitting by submarine tender Proteus, Tigrone departed Guam on 31 July and, after the usual stop at Saipan for torpedoes, arrived on lifeguard station.
On 11 August, the first reports of Japan's surrender were received, but, for two more days, Tigrone continued her patrols, approaching within 50 miles (80 km) of the shore of Sagami Wan as she pursued lifeguard duties.
On 13 August, with Navy pilots helping to spot targets, she bombarded Mikomoto Island, scoring 11 hits on a radio station and lighthouse tower.
On 14 August, Tigrone rescued another aviator who had been forced to parachute from his plane and, later in the day, spent an anxious half-hour attempting to evade persistent sonar contacts which turned out to be birds.
Later that month, she visited Washington, DC, for Navy Day activities and, late in December, reported to the Sixth Fleet at Philadelphia, Pennsylvania, for preservation procedures preparatory to inactivation.
That summer, she joined Submarine Division 62 operating out of Norfolk to begin activities evaluating new radar equipment and techniques for long range air defense.
Redesignated SS-419 on 3 February 1961, she was recommissioned on 10 March 1962 and underwent overhaul and conversion at the Philadelphia Naval Shipyard before reporting to New London for refresher training on 22 September.
Operating as a research and development vessel in cooperation with the United States Underwater Sound Laboratory, she began duties which would fill the remaining years of her long career.
She continued her research assignments, joining with submarine HMS Grampus in the early months of 1972 for a joint American-British oceanographic operation in the eastern Atlantic.
Into 1975, she continued research activities off the East Coast, which included a visit to Bermuda in March and operations with air units off Jacksonville and Atlantic City, New Jersey.