I haven't, but I'm in the higher elevations most of the time. Some folks think any snake swimming in the water is a cottonmouth. One time I heard a gunshot down in the bottomland in my back yard. I went on down to see what was going on, and an old retired football coach had shot a blacksnake on his side of the creek. He swore up and down it was a cottonmouth. Aren't cottommouths more of a swamp snake that can't tolerate very cold winters? You'd be suprised how many folks won't swim in some of the clean streams around here for fear of water moccasins. I'm talking about water that stays cool enough there's a few trout in there. Please correct me if I'm wrong, maybe there are cottomouths in the mountains, but I don't think so. But, I wouldn't doubt they are around in Southwest TN around the Mississippi River or maybe in some deepest southern parts of the state. If I saw one, no doubt I could identify it. I've seen my share of timber rattlers and copperheads, but I won't kill one unless it's near the house. I hate to even do that.