Shouldn't be TOO hard to do
It still upsets me how the heck he knew I was there in the first place. As i've said, i was creeping past the front DD rigged for silent, and then his ASDIC pings me straight away and they all know where I am somehow!!!
Although, I do believe that in real life, destroyers would use their active sonor all the time, even when they hadn't detected a sub. As this would've increased the chance in detecting one that was trying to sneak into the convoy. I remember the very FIRST silent hunter.
Those Jap DD's ran on active sonor all the time