This is a 650 acre inland lake. It was mapped a few times but that was long ago and it seems like you already know what happens with time. Depth finder would be just the simple digital gauge showing depth. It's really just 3 inputs and 2 out. 3 being, Depth, Speed, Trim position, 2 out being up and down... Idea is, more tilt UP to 70% if depth under 3ft, Tilt to 60% at 4ft, tilt 50% at 5ft.. Speed comes into play, if speed 8MPH and depth 3ft, tilt 80%... These figures are just an idea, this would have to be calibrated aboard the vessel to verify correct level.