At 12:47 on 24 March, "Wahoo" sighted smoke and began to make her approach. At 19:49, she fired a spread of three torpedoes at a large tanker (identified as "Takaosan Maru") which was fully loaded with fuel oil. The first two torpedoes exploded prematurely, and the third one missed. "Wahoo" fired a fourth torpedo which also missed. The target commenced firing deck guns at the American warship. The submarine surfaced after 14 minutes of ducking shots, gained position ahead, and dove. She fired another three-torpedo spread. One hit the engine room and sank the ship in four minutes.