Old thread being revisited here but I was never able to nut out the problem, I ran the 588 on a completely seperate battery, transducer opposite side to the power cables and wiring, & still got this noise or interference at trolling speed. When the screen clears up in these photos is when the boat is taken out of gear & not moving! Idle revs don't seem to aggravate it just the low range rpm's, could it possibly be turbulent water? I never thought it may be because the disturbance is the bottom half of the screen not the top
