[Erich dem Roten]

Meaning, why wouldn't, say, the lead escort of a convoy just blast actively all over the place 24/7? The others could stay passive, and the active might encourage a sitting U-Boat to move and get picked up, or even be picked up by the active sonar itself. Was there some sort of detriment to using active sonar so much, aside from broadcasting your location?

Also, I seem to recall reading something about how active sonar was far less effective when the target was very close (<5m) to the bottom. Something about reflecting the sonar waves back at the boat and giving lots of false positives.

I'm just posting these as they come to me, so forgive my rambling please. I just get curious, and sonar isn't exactly something you can just Wiki and understand.