You may have to go bird hunting! It's a pain when one of the escorts decides he wants to park himself above you and give hell for the rest of the war.
Black swans are the ship to be feared. They have good senors, lots of depth charges, a hegehog ASW mortar from 41 onwards and captained by some of the meanest ASW captains that ever existed in SH3

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I try to keep out of their reach at all times.

They've nailed my hide too many times to be counted!
Try and approach the convoy from a different side where a different escort is on patrol. you may get less interference!