A Case of Defective Torpedoes
The Wahoo’s next two patrols in the Sea of Japan were failures. During the first, the submarine fired nine torpedoes but didn’t sink or even damage a single target. Morton furiously reported that his torpedoes were defective. After returning to Pearl Harbor, new torpedoes were placed on the Wahoo.
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On September 9, 1943, it headed back for the Sea of Japan through the northern gateway, La Pérouse Strait. During the first week of October, the Wahoo sank four ships. It was after that that something went wrong. On the morning of October 11, Japanese anti-submarine forces, aware of the presence of a submarine, spotted an oil slick. They assumed it was a damaged submarine attempting to escape into open waters.