The problem with the "fish finding" features on some of the sonar units
out there is accuracy. At least this is my experience, but they always tell
you that there are fish even when there aren't. I fish in some really clear
water and my sonar (whichever one of the half dozen I've owned) and I can
see there aren't any fish under me but the sonar is telling me there are.
I think they seem to be best for locating structure and features of the
bottom that put you it fish likely spots. Sometime really big fish or balls
of bait are detectable, but if you think there's a bass under every one of
those symbols on your fish finder, you're in for a frustrating time catching
them, in my opinion.

Rich P