After an extensive overhaul at Mare Island—from 15–17 June—she returned to Hawaii and sailed on 9 July as part of a "wolfpack" ("Moseley's Maulers", commanded by Stan Moseley), with and , to prey on shipping in the Luzon–Formosa area. On the afternoon of 7 August, "Sailfish" and "Greenling" made contact with an enemy convoy. "Sailfish" maneuvered into firing position and fired a spread of three torpedoes at a medium tanker. One hit caused the tanker to disintegrate into a column of water, smoke and debris. It was not recorded in the postwar account.[In fact the "Sailfish" had sank the Japanese Kinshu Maru (238 GRT) in Luzon Strait in position 20°09'N, 121°19'E.