A lot of usefull information, did not expect that many replies, thanks a lot guys

!!
About the search pattern of escort destroyers, has anyone experienced this : after getting bored, the destroyers usually leave at top speed to rejoin their convoy, but most of the times, I see the last destroyer acting funny.
He seems to be following his friends, but at funny speeds. He accelerates for a second (litterally) and then stops and slowly drifts forward. This behaviour can be observed for hours, and quite frankly, makes it extremely easy to go back and shoot down the idle target at close range ( since the sub is already in the "deaf" area of the destroyer ).
Is he trying to listen? Or is this just a bug?