[Admiral Von Gerlach]

And YES the fleet boats of all services were originally intended to be a Battle fleet adjunct and the IJN continued to adhere to this view all the way thru the war pulling boats off misions to support surface fleet actoins. Commece raiding and other missions developed...the exception to this was the Kriegsmarine use of commerce interdiction from almost the start. And they had little surface fleet action to support anyway, though they tried when they could. So that was a valid thought....many service arms find their mission changes as doctrine impacts actual battle conditions and the sub service was no exception. I have seen some of the fleet manuals from the 20's, and 30's and hear of the development of doctrine and it was a long slow crawl from obscurity for the sub service in many navies....and the US achievemnts in the WWII were amazing and a validation of the sub arm in many ways, both for boat design and esp for crew and officer skills and performance in action. Other navies had their limitations and achievments too, includling the U boat service....all did their best but often the command ashore had their own views not always in line with what was possible at sea.