It might not be authentic to real life tactics. But you can preset your TDC for a 000 or 180 bearing attack and come to periscope depth while the DD circles. Either go ahead full or emergency reverse to get at least 300m away from destroyer. Set speed of fish to 10kts, depth 2 meters, AOB 90 (starboard or port depends on which way he circles) Aim just slightly behind bow as he will speed up at last second. Might take a bit of practice but will save you 2 or 3 hours of evasion sometimes.
