Decades ago the Hudson River in New York State was a toxic mess. The last thing anyone wanted to do was get near it because it smelled like a cesspool. Pete Seeger brought public attention to the Hudson through the Clearwater sloop. Riverkeeper had the political clout to get polluters to stop messing up the river.
Both great organizations are still around and still working to keep rivers clean. Check out the Clearwater. You can sail on it through the public or educational program or volunteer to work on it. Riverkeepers is now worldwide working to clean up polluted rivers everywhere.
This is the Clearwater sailing south on the Hudson River, past Manhattan's Grant's Tomb and Riverside Church. Photo courtesy of WorldIslandInfo.com