Submarines of the Imperial Japanese Navy
The IJN submarine arm did have a number of notable successes against American warships, however. During the Battle of Midway, administered the final "coup de grace" that sank the fleet carrier , as well as sinking the destroyer . A few months later, on September 15, 1942, with a single salvo of torpedoes, Japanese submarine sank the fleet carrier and damaged both the battleship and the destroyer . On November 13, 1942, the submarine torpedoed and sank the anti-aircraft cruiser , and a year later on November 23, 1943 the submarine torpedoed and sank the escort carrier , both with heavy loss of life. The had the distinction of both severely damaging the heavy cruiser , knocking her out of the war for a year, on October 20, 1942, and of also sinking (the only American submarine to be sunk by a Japanese submarine in the entire war) on November 16, 1943.
Monsun Gruppe
The German invasion of the Soviet Union in 1941 had ended the use of overland routes which were for the delivery of strategic materials from southeast Asia, and few Axis ships were able to avoid Allied patrols of the North Atlantic. Japan was interested in exchanging military technology with Germany, the Japanese submarine "I-30" initiated the submerged transport of strategic materials in mid-1942 by delivering 1500 kg of mica and 660 kg of shellac. Japanese submarines designed for the vast distances of the Pacific were more capable transports than the compact German U-boats which were designed for operations around coastal Europe; but large Italian submarines had proved ineffective for convoy attacks. The Italian Royal Navy ("Regia Marina") converted seven Italian submarines operating from BETASOM into "transport submarines" in order to exchange rare or irreplaceable trade goods with Japan. They were: The "Bagnolin", the "Barbarigo", the "Cappellini" (renamed "Aquilla III" in May 1943), the "Finzi", the "Giuliani", the "Tazzoli" and the "Torelli".