From the moment when an escort goes into it's attack run to when the last DC goes off you can use a burst of speed to either change course or depth.
The above is true if only one escort is on to you.
If more than one is tracking you then use short bursts of speed while the DC's are exploding. As Mel said, maybe 3-6 secs tops, this is enough for a course/depth change. Then drop to 1-2kts & pray.
