Nisshin Maru
Ten days later off Indochina, "Trout" launched two torpedoes at a cargo ship from and watched as the unidentified ship sank immediately. On 29 January, the submarine launched three torpedoes at a destroyer believed to be the Thai "Phra Ruang" (the former R-class destroyer HMS "Radiant") and watched each run true to the target. However, all proved to be duds. On 7 February, she sighted tanker "Nisshin Maru No. 2" moored off Lutong, Borneo. She made a submerged approach, launched two torpedoes at the target, heard one explosion, and observed smoke rise from the stern of the tanker. However, no sinking upon this occasion was confirmed. The "Nisshin Maru No. 2" was then towed and scrapped South of Ishigaki Island on 16 April 1943.