Evading: when to go flank speed?

[maillemaker]

Of course, by late in the war you should have noisemakers.

In which case I find it useful to go to flank speed, drop a noisemaker, and then go to 1 knot speed with a 15 degree course change.

But really, when they are on you, best just go to periscope depth and shoot them.

If you're lucky, they'll blow their own ass off with a shallow depth charge.