If you hear pinging move your boat as fast it goes and gain depth, when you are told of DC's in the water turn your rudder hard over either direction.
If there is no pinging, order silent running (Z) and set your speed to 2kts, moving at 2kts seems much quieter than the default 3.
Remember, depth is your friend
If you are at 160m the enemy DD may still be right behind you, but you have time to avoid any DC's.