I think that your mod idea is really needed, Stew!
I managed to add the Wasserbomben-audio (with critical help from Stormfly
) to the game. It is integrated in Stormflys Das Boot sound mod which really adds tension to the game and I suggest you try it. My stand alone version might be outdated if you are using latest TDW's Ui mod, but I can update later if needed.
But still I agree that depth charge attacks could be even more powerful. Now you basicly start to suffer when DC hits you. The boat should shake even if the DC explodes nearby, like the loading text says:
depth charge attacks were nerve wrecking, even if they didn't cause any damage. I would really like to see blinking lights and more shaking and ofcourse some reactions from the crew (now they just sigh and scrath their heads like they couldn't care less).