A water moccasin* swimming at the transient docks.
*Robert, a reader of this blog sent a note linking to an article about moccasins being the most commonly misidentified snakes around the water. It is certainly possible that I am wrong with the identification. I am not a biologist, but I have spent time in the field with biologists who have shown me both water snakes and moccasins, and pointed out the differences. I believed this to be a moccasin because of the diamond shaped head (we had a nice view at one point looking directly down from a dock), the snake's girth (moccasin's are much fatter than other water snakes) and the fact that at times the snake's entire body showed on the surface of the water. Not all those observations are visible in this particular view from a cell phone. That being said, I could be wrong (I'm often surprised to learn I'm right about something).
In any case it was an interesting sight on the waterfront. Thanks for the note, Robert.