Yes they do charge you to marshall, you are the eyes and ears for BASS if you will. You basically watch and send in weights over basstrac, a text system to keep up with the fisherman. I did it last year on Bull Shoals and it was a great learing tool for me. I viewed it as money well spent. I was paired with Hank Cherry, Kieth Poche, and Greg Vinson, each angler was a true professional and answered all my questions and showed me how and why the fish they were catching were at those spots. I learned some neat stuff. I really enjoyed it but would not do it on a lake I dont fish. It was really hard for me to watch as Hank caught over 100 fish on a jerkbait and not be able to get in on the action.