The fourth war patrol of the USS Jallao (SS-368), captained by Commander Joseph B. Icenhower, was conducted in the Sea of Japan. On August 8, 1945, the Jallao transited the Tsushima Strait and entered the Sea of Japan that night. Using the latest mine detection sonar, the Jallao was able to locate and avoid two mine fields as she transited the Tsushima Strait. The existence and location of these fields was confirmed by surrendered Japanese charts. On the night of August 10-11, 1945, the Jallao attacked a large unidentified ship and sank it with four torpedoes. The Jallao then proceeded to her assigned lifeguard station off northern Honshu and Hokkaido. Air strikes there were subsequently cancelled thus ending the need for lifeguard services. The termination of hostilities on August 15, 1945, deprived Jallao of further opportunity to attack enemy shipping. Her patrol was continued in the Tsugaru Strait until September 1, 1945.
Please use following link for more detailed information about Jallao's Sea of Japan tonnage scores.