I have the Eagle 480. Normally I run the sensitivity down around 65-75%, depending on water clarity (dingy to somewhat clear). This past week I fished a lake with extreme clarity and I ran the sensitivity all the way up to 92% to see the detail of the trees under water and still not getting too much clutter on the screen. I like keeping the sensitivity down trying to eliminate the clutter and picking up only the fish I have going under the boat, still allowing to see the brush/structure on the bottom. My best recommendation for you is to get off the auto settings and forget 'em and play around with your unit to build confidence in what you are seeing. Definitely turn off the fish ID symbols too.