That one doesn't seem to be easily available anywhere, I've also found
Fletcher's realism mod 2.3 (newer than the 2.1 at the Subsim page) which is supposed to be good, but it changes lots of things and it looks like some things might overlap with the uboatmod 2.1 or 2.2. I'm not looking for some perfect SH2 version, just some enhancements that improve the game while not ruining the balance. Some ships do seem to have incredible torpedo resistance.
I already installed the Vickers mods, as they do not seem to have any balance-affecting problems, just more special effects.