[jimmythegreek]

yes you are correct. U cannot see every layer and actual temps but the oxygen levels and temp affect the sonar sent thru the water and def show up on screen. I have been out trolling or pulling planer boards and spent alot of time marking fish and I can see the trout hugging the bottom foot of the thermocline in some reservoirs when there is a thermocline. I did mark a few fish under it that I beleive to have been lakers so theres no telling the actual layers and their depths to high accuracy, but its MORE than enough to set your DR up and figure out where they are suspending......the only way to do so is with a temp probe on your ball, like what you have used