6th Fleet (Imperial Japanese Navy)
Despite these advantages, IJN submarines achieved remarkably little during World War II primarily having in hindsight suffered from the antiquated strategy of the Imperial Japanese Navy General Staff, who viewed submarines as little more than scouts whose main role was to locate and shadow enemy naval task forces in preparation for a decisive surface conflict. Maybe the IJN General Staff was slow to change as the submarines were generally slow to dive, easy to track with radar and sonar, difficult to maneuver underwater, and less sturdy than their German U-boat counterparts.
Japanese submarine I-25
Two submarines were sighted on 11 October 1942 about off the coast of Washington as "I-25" was returning to Japan. "I-25" fired its last torpedo at the lead submarine, which sank in 20 seconds with the loss of all hands. "I-25" reported sinking a U.S. submarine, but the submarine was actually Soviet "L-16" which was sailing with "L-15" en route from Vladivostok to the Panama Canal via Unalaska, Alaska and San Francisco. United States Navy Chief Photographer's Mate Sergi Andreevich Mihailoff of Arcadia, California, was aboard "L-16" as a liaison officer and interpreter, and was killed with the remainder of the submarine crew. The United States Navy Western Sea Frontier denied loss of any submarine and withheld information about the Soviet loss because, at the time, the Soviet Union was officially neutral in the war between Japan and the United States.