Your timing of your post is funny. I JUST called the law enforcement office (I forget the actual name) for Falls Lake in NC to ask about having my gun with me as well (I have a ccw permit) I think it really makes sense on the water to carry something. The officer told me so long as I have my permit and am obeying the other laws (not drinking on the boat) I am allowed to carry. He also said that carrying to and from the boat which I have to pass through game lands is also fine. I made sure I had his name just in case I need to reference our conversation with another officer. Good luck.
Chris
Chris