I was wading in a trout stream in the hills of So. Cal. a while back. Had hip boots on, and when I walked upstream as far as I cared to, I couldn't get out because of the brush. So, I walked back downstream to reach the entry point.
Just as I was about to step on the bank, I saw the rattler. It saw me about the same time and we both had the same idea. RUN!!!!!!
It went one way, and I went the other. I looked a lot harder for a different way out of the water this time!