Chain o lakes state park is free to launch and short drive to Marie. Stay in the channel on grass lake. If you want to launch on Channel, contact Musky Tales. He has a launch on 173.
I just started musky fishing on the Chain. Was only out 1 time. Cold and windy day a few weeks ago. I was trolling grandmas on the breaks on Marie. Wasn't 100% positive I was working the right areas until a guide showed up and was trolling the same area I targeted. The owner at Musky Takes suggested deep crainks or plastics like bulldogs. Hope this helps.
I did peel off to channel and found some good breaks and flats. Both lakes don't seem to difficult to figure out.
Seeing the reports here, it looks like some fish are migrating shallow, so my mind says breaks and noonrise/ moonset try a bit more shallow and use suicks and supershad and jerkbaits.
Seeing I have only tried the chain once, hopefully someone else will chime in.