Thanks everybody
I made it to the lake Thursday and finally got it set up to my liking. You guys are right with your advice and here's what I did after thinking about it for about a month. I went to the bank and got a tree that represented the smallest amount of brush that I wanted to show up, dropped a bouy and sank the tree. Then I put it on manual and started turning the sensitivity down until the tree just barely showed up. For me that number was 50%. Also, another big help to me was the surface clarity setting. The default is off but you can change it to low, medium or high. Somehow this reduces the power near the surface but increases power nearer the bottom. Setting this to medium really cleared the water column up where I had vertical lines and other junk cluttering the screen. And, as SpeckWick says, setting the keel offset for transducer on trolling motor is a big help in reading the height of brush as well as the depth of fish. No more having to add 18" or 2' or whatever to what the graph is telling you. Just read it direct! Hope this helps the next person in setting up their Eagle. One other thing though. I am not yet able to see the advantage of arches over fish ID. I switched back and forth several times and I have to admit...I kinda like the fish symbols. But...95% of my fishing is done on brush or other structure that I have put in the lake myself and I am going to fish these spots because I've caught fish there before, whether I see fish on the fishfinder or not. I gained alot of confidence in what the fishfinder is showing me as far as brush this week but I am not confident enough to really trust that if there are no arches then there are no fish! Thanks.
Mark