One thing that i forgot to mention is that max elevation while it defines the downward angle of the beam, it also defines the blindspot of the sonar beam. The more downward angle, the longer the escort can keep contact. Under currrent settings, Late war escorts might be pretty accurate.
(see pic
http://www.ducimus.net/sh3/late_war_sonar.jpg)
In the future i might change the max elevation from 108, 112, 120 to say... 108, 112, and 116. Or maybe even 106, 108 and 110. Not sure yet.