@redwine
i'm not so sure. with the settings i'm testing, w/out changing min/maxheight, i go green
in front of the escort, even if they've been actively pinging me. distance depends on depth. if you're making noise however, you stay red until they drop the dc's. so if you're green, and change course, you can move away from the drop point. if you're green and wait until the escort is directly above or past, you can hit the accelerator and they won't hear you, allowing you to evade.
i agree that w/out some sort of alarm, the escorts don't actively search for you. that's too bad, as in irl, asdic was pinging 24/7 at sea. if we could find the state variable that makes a dd go "on alert"...
re visual elevation -- let's not forget about aircraft. if we set the min elevation as 0 in ai_visual, we'll be nerfing air patrols -- they won't be able to see below their nose.
keep at it, guys. we may be hosed by the lack of an sdk and limitied by the basic game ai, but at least we can make things a little better.