I've enoucoutered a few water moccasins at the lake that tend to annoy me. I can deal with them on land, but when they're swimming right towards you, that'll make your nuts go right up inside, especially when you're waist deep in the water. You can splash, throw schit, whatever, they still keep coming at you. I don't know if they'll actually strike if they get up on you in the water like that, but I'm not sticking around to find out.