Noise

[silentwayIII]

Thanks for all of the answers, but a little clarification to this thread is needed on my part. When I was going at 1kt, I was in silent running mode. Whenever I approach a warship I am in silent mode...even if the warship is traveling at a high rate of speed.
When I got pinged, at 2000 meters plus, the escort had already begun to turn in my direction...so I assume, he heard me. Is exploratory pinging, or even random pinging built into the game or major mod? If this is the case, I could understand getting caught by a random pulse but this, I don't think, is a feature of the game/major mods.
I'm well familiar with the aspect issue when trying to evade or just plain getting out of dodge and so always try to reduce my aspect ratio.
I've tried Jungman's sensor file (w/o crashes) only when playing the XXI to attempt to compensate for the submarines lower noise signature and non-modelled creep engines. I think in this case, its probably a little closer to real...with the XXI anyway as far as noise is concerned. When I'm being pinged, its right on target if I'm within decent echo return range.
Don't want you to think I'm not reasonable in regards to the XXI's survivability...I've been sunk in that boat also. The thinking like a U-boat captain is a must and that is the way I play.

Thanks again.

silentwayIII