I agree you would think that but it is not. The fishfinder in the front of the boat will be reading fish while this one does not. If that is not convincing enough, I can cover alot of water trolling, etc and not the first fish will appear on screen, for about six months now. So either Barren and Nolin lakes do not have any fish and the front fishfinder is lying...or it is messed up. I saw where you can go to humminbird.com and get software updates. I guess I will give that a try. You can change which transducer you want to use and it is set on the dual beam so I don't know what else to try.