I have side scan on my garmin. I don't use it often only in shallow water, bass, perch , walleye.
My question is, out on ontario I turn it on and the bottom shows large dark areas. With very light color areas around mixed in. Not bait or weeds I'm talking 150 to 200 feet. Am I seeing rock bottom dark, covered in zebra mussels against Sandy bright or mud bottom? What's your thoughts.