Description: Japan started the war with 63 ocean-going submarines (i.e., not including midgets), and completed 111 during the war, for a total of 174. However, three-quarters of these (128 boats) were lost during the conflict, a proportion of loss similar that experienced by Germany's U-Boats. Most of the surviving boats were either dedicated to training roles or were recently completed and never saw combat. Of those which saw significant combat, the toll was very grim indeed. For example, of the 30 submarines that supported the Pearl Harbor attack, none survived the war.