Originally Posted by Tessa

The Allies wised up after WWI and began re-capturing real-estate where the training grounds for the new officers and trainee capitains were. It became more of a trial by fire than a real training program after ~ 1943, only a handfull of officers really became proficient at the job like Topp and the (promoted) crew of U-48 which ultimatey comprised what remained of the combat elite.

After some researching I finally figured out the answer to your earlier question about a NCO w/o any pips. Found a much more detailed chart of all the enlisted ranks. Many of the odd looking ranks (like the blank nco's, or ones with 2 horizontal stripes across them) generally denoted NCO's that were Officer's in training.

Since (especially the Kriegsmarine) suffered from a full staffed leadership hierarchy many crewman would automatically be promoted to NCO ranks after 4 months as a sqaud leader on patrol, and then again in another 4 months if not promoted otherwise (and survived!). In a way, for the wrong reasons those that survived long enough to go on multiple patrols either were lucky or were doing something right with a 75% fatality rate; having the automatic promotions (under the conditions) I don't think were a bad thing as anyone that did get them were considered seasoned and (theoretically) knew what they were doing by then.