Blackfish for nearly 40 minutes, but in the end she outran them. Blackfish resumed her pursuit of the convoy and sighted its smoke at approximately 11:11 on 23 November 1943. Davidson observed that there was one less ship present in the convoy, which led him to believe that Blackfish had in fact sunk one of the cargo ships in the previous attack. Blackfish began an attack approach but the escorts detected her some off and forced her to withdraw. Blackfish continued to track the convoy well into 24 November 1943. She reached an attack position at 23:08 on 24 November and launched a spread of six torpedoes at the stern of an unidentified cargo ship in the Japanese column located at . Blackfish′s crew heard five explosions between three and four minutes after firing, but could make no observation of the resulting damage because the convoy’s escorts quickly closed in. They pursued Blackfish for a full 30 minutes, but at length she escaped unharmed. Blackfish sighted a Japanese convoy on 26 November 1943 and then shortly thereafter lost track of it in a rain squall. She reacquired the convoy a few hours later, but as she assumed an attack position on the surface, one of the convoy’s submarine chasers attempted to engage her, forcing her to dive. Over the course of several hours Blackfish endured a sonar-guided attack by more than 20 depth charges. Davidson observed that Blackfish′s rudder was exceedingly loud, and he believed that the Japanese ability to locate Blackfish was directly related to her inability to keep quiet. Following a prolonged siege, the Japanese broke off their attack and Blackfish resumed her patrol. Blackfish left her patrol area on 28 November 1943. She stopped off at Tulagi for fuel on 1 December 1943, and on 4 December she made contact with her escort aircraft. She then proceeded to Milne Bay on the eastern tip of New Guinea, where she completed her sixth war patrol after 46 days at sea, 32 of them in Japanese-controlled waters. With her crew in high spirits, she underwent a standard two-week refit at Milne Bay. Blackfish′s patrol was deemed "successful" and her crew was authorized to wear the Submarine Combat Patrol Insignia. As Blackfish′s first war patrol in the Pacific Theater, it served as a learning experience for both her commanding officer and her crew. Although Blackfish had attempted both of her