I did this little workaround trick some time ago. You can listen creepy sound on hydrophone while ship is sinking and your sub is underwater.
Please test it and report if fix is working as it should.
I only modified
particles.dsd file, so the majority of mods should be compatible.
I also provide modified sinking hydro sound.You can remove it if you don't like it.Mod works fine with stock one.
http://www.mediafire.com/download/d4..._hydro_fix.rar