I have to agree Idk that the boats are causing much damage to rivers considering most flood or get really high every spring and wash out and reshape the river. I do my best to be courteous, the only problems are when canoers aren't courteous to you and never give you a break to run through a long riffle. I've been on rivers before where you have canoe rental places that shuttle groups up river non stop it seems like, and I have to stay on plane to make it through long shallow stretches. I always try to wait for a break in canoers so I can make my run, but sometimes they just won't give you break even when I've been sitting there waiting and asked people to stop. I try to avoid rivers like this, but in my home state of mo it's hard. When I visit sometimes it's nearly impossible on summer weekends as just about every good river within reasonable distance of STL where my family lives has some canoe outfitter operating on it. A lot of times they use public launches/take outs and choke them up with canoes making it hard to pull out as many of the people block the ramp with canoes and won't move.