Pontoons or canoes would be great in the upper section but rather dangerous in some parts of the lower section. The chute pictured in the lower section pictures really moves when the water is up and its much bigger than the pictures indicate. There are standing waves in the three to five foot range in the middle of it.
I'll have to check into canoe rentals on the Saugeen - lots on the Grand. I assume there has to be some since it is a tourist oriented area. I'll see what I can find out.