Submarines of the Imperial Japanese Navy
The Imperial Japanese Navy's doctrine of fleet warfare ("guerre d'escadre") resulted in its submarines seldom posing a threat to allied merchant convoys and shipping lanes to the degree that the Kriegsmarine's U-boats did as they pursued commerce raiding against Allied and neutral merchant ships. During the war, IJN submarines did sink about 1 million tons (GRT) of merchant shipping (184 ships) in the Pacific; by contrast U.S. Navy submarines sank 5.2 million tons (1,314 ships) in the same period, while U-boats of Nazi Germany's "Kriegsmarine", the IJN's Axis partner, sank 14.3 million tons (2,840 ships) in the Atlantic and other oceans. During the last two years of the War in the Pacific, many IJN submarines were also occupied serving to transport supplies to isolated island garrisons, ones that had been deliberately bypassed by the Americans and the Australians and which could not be reached by surface transports because of blockade by Allied warplanes and naval vessels.
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.