During the 1930's several experienced (WWI) U-Boat Captains spend "exchange time" with the Japanese Navy. Additionally, IJN submariner observers go to Germany and take sub rides and time at Doenitz' HQ.
Due to this, while scouting for the fleet has not been removed from the requirements of the submarine force, all subs not required for such duty are to be used for anti-commerce roles. Naturally, if while attacking convoy routes, warships are encountered they are to be the focus of attacks. However when Pearl Harbor is attacked long range Japanese submarines are in place along the US-Hawaii route, and one each just outside Los Angeles and San Francisco. Plans are made to cover the US-Australia route as well. While not true wolf packs, several submarines will set out along a line centered about one that carries an aricraft, which will be used for scouting and finding convoys. Japanese torpedoes, especially because of long range, give attacking submarines a better chance of evading escorts.
With the change in tactics, before the war the IJN converted several large Marus to sub tenders, allwoing greater forward basing abilities on captured islands.
At a minimum this will require more US escort assets to be moved to the Pacific, and will result in greater losses of materiel (and possibily troops) shipped to Hawaii & Australia, as well as the loss of merchant tonnage.
Any thoughts on this? I realize this will require a significant mental shift in IJN submarine operations, but they weren't totally stupid & so the exchanges in the 30's & sub riders on U-Boat patrols 1939-41 might do this.
Due to this, while scouting for the fleet has not been removed from the requirements of the submarine force, all subs not required for such duty are to be used for anti-commerce roles. Naturally, if while attacking convoy routes, warships are encountered they are to be the focus of attacks. However when Pearl Harbor is attacked long range Japanese submarines are in place along the US-Hawaii route, and one each just outside Los Angeles and San Francisco. Plans are made to cover the US-Australia route as well. While not true wolf packs, several submarines will set out along a line centered about one that carries an aricraft, which will be used for scouting and finding convoys. Japanese torpedoes, especially because of long range, give attacking submarines a better chance of evading escorts.
With the change in tactics, before the war the IJN converted several large Marus to sub tenders, allwoing greater forward basing abilities on captured islands.
At a minimum this will require more US escort assets to be moved to the Pacific, and will result in greater losses of materiel (and possibily troops) shipped to Hawaii & Australia, as well as the loss of merchant tonnage.
Any thoughts on this? I realize this will require a significant mental shift in IJN submarine operations, but they weren't totally stupid & so the exchanges in the 30's & sub riders on U-Boat patrols 1939-41 might do this.