I have told this story before but I will again. I have had one chase me. One night after college a buddy of mine and I were fishing a small stock pond that we grew up fishing and were going to spend the night out there drinking beer, fishing, and sleeping in the truck. We pulled a hay trailer down to the bottom because the pond was a little down and nobody had mowed all year. As you would expect in towards the end of summer the first 3 or 4 feet from the water line was just mud, so we pulled the trailer up parallel to that.
Now that I set the scene, I watched a cottonmouth swim from the darkness directly towards me. Obviously freaking me out, I jumped up on the hay trailer, looked back, and that snake was in my boot prints from where I had been standing. After moving off he did it again a couple of times before I took a swipe at him with a 2 iron. I missed.
I shot him the next morning with a 20 gauge. Stood in the same spot and he was there in less than a minute. One of the craziest things I have seen in the wild.
Strangely on that same night we pulled the biggest bass I have ever seen out of that water on the first cast. LIttle pond that hadnt been fished, occasionally gets flooded out by a creek, and has more than once almost dried up, grew some giants in the ten years between high school and that night.