If you have a sound editor, find this directory:
X:\Program Files\Ubisoft\SilentHunterIII\data\Sound
In there you will find 2 files named:
Collision_AntiSubmarineNet_ext.wav
Collision_AntiSubmarineNet_int.wav
Open it with your sound editor, and reduce the decibels to a comfortable level and save.
Voilà , no Starforce there eh!…