Side scan. Question

[Bassin Bob]

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. 

[Yankee Troller]

I've noticed the same things, but I can't explain it.

[Sk8man]

Deeper depressions in the bottom that it can't focus on when already focused on bottom?

Edited August 17, 2020 by Sk8man

[guffins fisherman]

I noticed it too. I just figured it was too deep for side scan to be effective and went back to trad. or downscan sonars. I do like the looks of it in shallower water.

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