I let snakes live and let live...except copperheads and Cottonmouths. Steve Irwin caught every kind of poisonous snake in the world except for one...the water moccasin/cotton mouth. He said they were vicious and unpredictable and when they bite they bite not once to get away, they continually bite the target. Think of cottonmouths as the Kathy Griffin of snakes.
I dont like to kill any kind of snake. A good size cottonmouth was in the road in front of my house in Febuary.For the most part if you leave them alone everything will be fine. As long as you see them first. A couple years ago I was casting a net for shad standing on a river bank. Me and my wife and a cottonmouth cane from behind us about 3 feet from us and went into the water. We never saw it until it was right beside us.