What is the appropriate reaction when you encounter a snake in the wild?

Of all the moccasins I have seen, I have only been chased once. I was in a canoe. There is a theory that they protect their nesting sites after they lay their eggs. I'm not sure if that was ever proven or not. They don't actually look after their young, but there are some snakes that will protect their eggs. Many species of pythons actually "maternally incubate" their eggs, king cobras have been seen protecting their nesting site a few times, so it is the most likely scenario.