The German U-Boat Force of the Pacific
When it comes to U-Boat warfare, most people think of U-Boats sinking Allied ships in the North Atlantic. However, U-Boat prowled everywhere, including places like the Caribbean and South Atlantic. One far off area of operations was the Indian Ocean and Pacific Ocean around the waters of Indonesia, the Straits of Malacca, and the South Pacific. Called Monsune Gruppe, the U-Boat force was founded in 1943 when a first wave of a dozen U-Boats sailed to Asia. Submarine bases were founded Penang in Malaysia, Kobe in Japan, and a handful of small repair and supply bases throughout Indonesia. A few Italian submarines also sailed east to join the group, but Italy surrendered halfway through the journey, and the submarines surrendered at South African ports. One Italian submarine that was to be a part of the force, the Cappellini, attempted to surrender but was captured by the Japanese, then turned over to the Germans. Since it operated so far away from Germany, Monsun Gruppe was often dependent on Japanese supplies. In addition, six Japanese submarines joined the group, one of the few instances of direct cooperation between German and Japanese forces.
By 1943, Allied forces had developed tactics and technology to counter submarines. Among them was the use of naval aircraft patrols. Considering that the Pacific Theater was chalk full of carrier based aircraft, the environment for Monsun Gruppe was in many ways more dangerous for the U-Boats than the North Atlantic. As a result of these factors, Monsun Gruppe’s success was modest compared to other theaters of operation. From 1943 to 1945, Monsun Gruppe sank 66 Allied freighters. In addition, the unit delivered small amounts of strategic materials to Japan from Germany. Out of the 44 U-Boats, six Japanese submarines, and one Italian submarine that took part in Monsun Gruppe, 28 were sunk, most by US Navy aircraft. When the war ended, most surviving U-Boats were scuttled, their crew surrendering to the Allies. Six U-Boats were either turned over to or salvaged by the Japanese Navy, all of which were scrapped or scuttled after the war. The Italian submarine Cappellini, then operated by a mixed German and Italian crew, was returned to the Japanese Navy and manned with a mixed German, Italian, and Japanese crew. When Japan surrendered, it was seized by the US Navy, and later scrapped in 1946.