Marinette to Fayette in Green Bay
You are right about Horseshoe. It is thick with grass and I generally don''t like to anchor there after the 4th of July. You are better off across the passage in Nicolet Bay. It is very crowded but the holding is good in the center. Horsehoe is prefered in a northerly wind or you can anchor off the southeast corner of Chambers Is. The North west corner of chambers has a nice anchorage as well. This is my prefered spot. In a west to northwesterly you can anchor off the eastern shore of chambers with clear sand bottom but you need to thread your way around the shoal extending off the southeast corner.
Detriot harbor will be a challenge with a 6''draft due to low water this year but if you are carful in the channel you should be OK. Follow the channel to the midpoint of the bay and take a right and drop anywhere. Jackson Harbor is small and the approach is a little hairy. I don''t know if you need that. Fayette fills up fast on the weekends so try to get there before the Saturday crowd. It is a beautiful place and very popular from July on. Good Luck and have fun.