The Kriegsmarine was clearly the least Nazified branch of the Wehrmacht. American Naval commanders objected to the 10 year prison sentence handed down to Doenitz at Nuremberg. The Kriegsmarine may have been fighting on the side of an unimaginably foul and evil regime, but they conducted themselves with as much honor and chivalry as circumstances would allow, from the top on down to the lowliest seaman. It is manifestly wrong to equate the Kriegsmarine with the Imperial Japanese Navy.
You are tilting at your own windmill.
I just said it's pretty doggone near impossilble to do so since no comprehensive "after the war" interrogations/interviews of the German Navy operational personnel were actually possible ~ the sample base was just too small!
Must be some reason why we ended up exterminating those guys though ~