I like 100 ft both ways for general coverage just because I can pick out things and yeah, in shallows you can get blockage depending on how near the tops of the weeds are. Its still way better than no side scan. If you have a little downward angle to the sonar wave it will travel along and show the tops and show dark areas for breaks in the weeds. Get the weeds to high and ain't nothing going to help you.

WarrenMN