Sonar classes are available on Lake O Pines , Brandy branch, Martin creek and Caddo. I've taught two classes on Wright Patman.
I use my side scan sonar on any lake deep or shallow, it's another tool that can save you a lot of time.
To answer your question.
On Caddo I use my Side scan to find non emergent grass, cypress stumps, brim beds, ditches, creek bends. You can learn a lot with it.
Caddo Lake Guide