[Dread Knot]

I'm wondering if maybe it shouldn't be the other way around. Most U-Boat crews were pretty relentlessly trained already during their workup in the Baltic. Perhaps drills could be something you must do to prevent them from losing their edge and proficency? Otherwise, on one of these long patrols to the South Atlantic your crew could build up so much experience that they'll be unstoppable pros without every having met the enemy unless it's capped in some way.