The thing about fresh water in Africa, and in South America I would imagine, is that regardless how good it looks you can NEVER drink it and you can NEVER swim in it. I mean NEVER.
But you have to say that when it is 30 degrees Celsius ans super humid, and the water is clear and cool with a firm bottom that you can see, it is hard to resist!
I wonder, can you swim in the fresh water in South America?