my goal this winter is to become a lot better with my depth finder. i read some tips and tried a few things while i was dropping brush this evening. i set my sensitivity to 80%, turned of my fish i.d., took it out of auto mode, put my grayline on 50%, the surface clarity was on high and for a while the unit did fine. i was sitting in 10 ft of water and there was a black cloud from 10-7 ft deep that looked like the bottom. any idea what i'm doing wrong? i have an eagle accura 240