I always recommend SH3 Commander, which is not a mod but an external tool that lets you control several game parameters - deck gun reload times, crew fatigue rates, wave heights with different weather, more realistic crew loadouts, time spent in base between patrols, and a lot more - with a single mouse click. It also adds historically accurate names to the ships you sink, and has a database of all known crewmember names, which it then recombines into separate names giving a total of 1.7 billion possible names.
The best part is, it works outside the game which makes it reasonably stable.
http://www.subsim.com/radioroom/down...o=file&id=4789