[DeepSix]

Yeah, I wondered about that ^ too. IIRC Blair consistently makes it sound like Withers (or Lockwood) knew something about German tactics, and I think it's likely that there was a general awareness of them. There is always an intelligence report about the enemy, it's just a matter of how detailed it is.

But I also think it took time for gathered intel to trickle down to individual skippers. First there has to be some espionage or interrogation of captured u-boat crews, or at least a study of RDF readings from the last convoy attack. Gradually, comparisons of multiple enemy approaches are pieced together and assembled into "what they appear to be doing when they attack." And at that point, pride runs deep. Doubtful if anybody would have advocated simply copying German approaches outright. Japan was a German ally - if we had attacked them using the same tactics as their ally, how long would that have worked? And there's always an underlying desire to figure out what works and then try to improve on it. As Torp said, the doctrine of submerged approach on sound bearings was driven into submariners' heads at the point of a court-martialing if they deviated from it, because the Japanese fought in their own unique way, and we had to figure out how to best counter them. We were studying the Japanese rather than the Germans, because in the 1930s the Japanese were a greater strategic threat (from our point of view).

I still think, though, that basically it took a little while for everybody to realize that there would be no Jutland in this war. So on that note I might play devil's advocate and suggest the U.S. actually learned its lessons very quickly in adapting to an unforeseen strategic situation. Deprived of the ships with which it might have tried to fight a second Jutland, the U.S. found itself in an off-balance position, not unlike that of Germany, and in combat with a superior fleet. Not quite what I'd call a mosquito fleet situation but not far from it either.

While the Japanese were dithering around trying to get us to the decisive battle, we were cutting off the fuel that they planned to fight it with. One might also argue that we learned quickly because we had already broken Japanese naval codes, and once German codes were compromised also, we could accumulate information and react even more quickly....