Yes when you are cruising above 15 mph, the fish appear as a line up and down or a spec. I have mine set to show yellow as strongest returns. So when I see yellow lines on screen, I might slow down to 10mph or less to check them out. The faster you go, the more water you are marking, so even at 5mph instead of drifting at 1 or trolling at 2, the fish might seem to be more, but when you slow down they dissapear or break up.
Rickerd