Always thought it would be nice to be able to give lone allied merchantmen the opportunity to surrender and let they crew board the lifeboats before sinking (or even boarding them). In a previous game I was lucky enough to be able to board a half sunk Liberty Ship only to discover it stocked to the gunwales with gold bullion. i wish I had done a screenshot, never been able to reproduce it. With my extended store I managed to load up with sufficient gold destined for the Bank of England to keep me in torpedoes and schnapps for the rest of the game.

Talking about schnapps...including it might steady the nerves of the more PTSD'd crewmen. Having served in the military the idea of 'discipline' reducing with stress annoyed me; you should replace 'discipline' with 'morale', a lot more realistic.