you took a beautiful picture though, i love snakes. rest assured, cottonmouths USUALLY try not to bite. there was a study done on them. Here's part of an article on them from Wikipedia.
Within their range, cottonmouths have a reputation as being aggressive snakes. However, in tests designed to measure the suite of behavioral responses by free-ranging cottonmouths to encounters with humans, 51 percent of the test subjects tried to escape and 78 percent used threat displays or other defensive tactics. Only when the snakes were picked up with a mechanical hand were they likely to bite.[11]
In addition, many of the snakes that did bite did not inject venom. Such a "dry" bite could also be another, more serious threat display. Unlike most snakes, including the copperhead, when startled the cottonmouth often will stand its ground and open its mouth ("gape" or "smile") to warn predators to stay away. That behavior is many times seen as aggressive, but if left alone they will leave.
You're lucky you didn't meet a Copperhead. Those are very aggressive and will try to bite you sometimes if you aren't even doing anything.. The Copperhead isn't as venomous as the Cottonmouth though. But the Rattlesnake is more venomous than both
. They usually do deliver a dry bite though, and whe nthey do inject venom it's not super serious and very rare to kill given that you seek attention. It's weak enough venom that they only give you antivenom in real serious cases. So yes he's a bad boy but not one that can kill you.
K I'm done being teh Steve Irwin of the board haha.
