Barbel arrived at Pearl Harbor on 21 June 1944 and commenced preparation for her first war patrol. From 15 July 1944 to 4 February 1945, she carried out four war patrols and is officially credited with sinking six Japanese ships totaling 15,263 tons.
Barbel departed Fremantle submarine base, Western Australia, on 5 January 1945 for the South China Sea on her fourth patrol. Late in January she was ordered to form a "wolfpack" with Perch and Gabilan and patrol the western approaches to Balabac Strait and the southern entrance to the Palawan Passage. On 3 February, Barbel sent a message reporting that she had been attacked three times by enemy aircraft dropping depth charges and would transmit further information on the following night.
Barbel was never heard from again. Japanese aviators reported an attack on a submarine off southwest Palawan on 4 February. Two bombs were dropped and one landed on the submarine near the bridge. The sub plunged, under a cloud of fire and spray. This was very likely the last engagement of Barbel. She was officially reported lost on 16 February 1945.
^ abcdefgBauer, K. Jack; Roberts, Stephen S. (1991). Register of Ships of the U.S. Navy, 1775–1990: Major Combatants. Westport, Connecticut: Greenwood Press. pp. 275–280. ISBN0-313-26202-0.
