sub won't stop diving

[Pepe le Moko]

Okay i got sunk while trying to attack a convoy.

It is probably not the proper way to do it, but what i did was put myself in the path of the convoy at 20m under the surface and wait for the leading destroyer to pass above me.

The thing is that i got spotted, i suppose i was not deep enough. it was during the day but i had silent running on and wasn't moving.

Anyway my problem was that after i saw the destroyer head straight for me and noticed my stealth indicator was red, i dived. I got depth charged but that's not what killed me.

The sub wouldn't stop diving. I kept trying to stop diving and even blew the ballasts but that didn't seem to do much. So what gives?