Pampanito's first war patrol, from 15 March to 2 May, was conducted in the southwest approaches to Saipan and Guam. She served on lifeguard duty south of Yap, then scored two torpedo hits on a destroyer before sailing for Midway Island and Pearl Harbor for refit and repairs to a hull badly damaged by depth charges.
Second patrol, June - July 1944
Pampanito's second war patrol, from 3 June to 23 July, took place off Kyūshū, Shikoku, and Honshū. On 23 June, a submerged Japanese submarine fired two torpedoes, just missing Pampanito. On 6 July, Pampanito damaged a Japanese gunboat, and 11 days later headed for Midway Island.
Third patrol, August - September 1944
Pampanito's third war patrol, from 17 August to 28 September, a wolfpack operation with submarines Growler and Sealion, was conducted in the South China Sea. On 12 September, she sank the 9,419-ton SS Rakuyō Maru, which unfortunately was transporting 1,350 British and Australian prisoners of war (POWs), also the 5,135-ton tanker Zuihō Maru, and she damaged a third ship. The Japanese survivors were rescued by an escort vessel, leaving POWs in the water with rafts and some abandoned boats. A total of 1,159 POWs died, of whom some 350 in lifeboats were bombarded and killed by a Japanese naval vessel the next day when they were rowing towards land.[9] On 15 September, Pampanito moved back to the area of the original attack and found men clinging to makeshift rafts. As the sub moved closer, the men were heard to be shouting in English. Pampanito was able to pick up 73 British and Australian survivors and called in three other subs, Sealion, Barb and Queenfish, to assist with the rescue. She then set course for Saipan, disembarked the survivors, and continued on to Pearl Harbor.[10]
Fourth patrol, October - December 1944
Pampanito's fourth war patrol, from 28 October to 30 December, took place off Formosa and the coast of southeastern China with Sea Cat, Pipefish, and Searaven. Sinking the 1,200-ton cargo ship Shinko Maru Number One, 19 November, she damaged a second ship before putting into Fremantle for refit.
Fifth patrol, January - February 1945
Pampanito's fifth war patrol in the Gulf of Siam, from 23 January to 12 February 1945, with Guavina, was highlighted by two sinkings, the 6,968-ton cargo ship Engen Maru 6 February and the 3,520-ton passenger-cargo ship Eifuku Maru on 8 February.
Sixth patrol
Refitted at Subic Bay, Pampanito returned to the Gulf of Siam for her sixth war patrol. Operating with Caiman, Sealion, and Mingo, she sighted only one target before sailing for Pearl Harbor.[citation needed]
1945–1971
From Pearl Harbor the ship proceeded to San Francisco for overhaul, departing for Pearl Harbor again 1 August. With the end of the war, she was ordered to return to San Francisco. She was decommissioned at Mare Island on 15 December 1945. She remained in reserve until April 1960 when she was assigned to Naval Reserve Training at Mare Island Naval Shipyard. Reclassified AGSS-383, 6 November 1962, she served as a Naval Reserve Training ship at Vallejo, California, until she was stricken from the Navy Register on 20 December 1971.[1]
Pampanito was turned into a memorial and museum at San Francisco on 21 November 1975,[2] transferred to the Maritime Park Association (formerly the National Maritime Museum Association) on 20 May 1976, and opened to the public on 15 March 1982.[11]
The USS PAMPANITO Amateur Radio Club brings the radio room to life on the 2nd and 4th Saturdays of each month using the callsign NJ6VT – NJVT was the boat's call sign during WWII. Ham radio operators may contact the boat on 7.260 and 14.260 MHz using voice, and on other frequencies using Morse Code.
She flies a broom from her mast, indicating a clean sweep: a successful patrol that "swept the enemy from the seas. In total, she sank six Japanese ships and damaged four others with a total of more than 27,000 tons of enemy shipping sunk.
Pampanito has completed four maintenance dry dockings since becoming a memorial and museum.[13] "The Pampanito still has several working parts, including one torpedo tube, the periscope, engines, galley and ice-cream maker."[14] The museum runs educational programs including one that allows organized groups of children and adults to sleep overnight in the submarine's 48 bunk beds.[15]
The ship was closed to the public and moved to a dry-dock on 23 September 2016 and returned from Bay Ship & Yacht in Alameda, CA on 14 November 2016 and is currently open to the public.