The snorkels I've seen installed on American subs were done in 1950 and later. Balao's was installed in 1950. We had to copy captured U-Boats for those.
Hey, Americans don't invent EVERYTHING! I think I remember that we even copied a captured German torpedo for our Mark 25. I believe the Mark 14 was even patterned on a German design. Anybody want to contribute facts to supplement or destroy my vague memories?
We did introduce a much better ballast system with our negative and trim tanks. We did come up with the Position Keeper to suppliment the TDC and give our subs the world's first predictive targeting system for submarines. We also invented an efficient bureaucracy which ensured that top quality torpedoes were provided to our sub force from the first day of the...... ah, strike that
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