My 788ci did not start showing the two bottoms in shallow water until I did the update. It does not bother me. That is the way my old fish finder worked. Is there a way to set the bottom of the screen so it will always stay on say 40 ft. I cut auto depth off but the bottom of the screen will still jump up and down when I go from deep to shallow. I would like the bottom of the screen to stay at 40 ft. Thanks for the help.