The marina my slip is in has very strict policies, that no swimming is allowed within the marina dock area. Still I see people "Taking a dip" to cool off. Right next to the prop. I wonder why he was backing up? Usually you make a really wide swing around the person to get the rope back to them. Very sad to see this happen I hope he does well with recovery. My wife has scars on her leg from a prop hitting her during a boating accident where she was thrown from the boat and got run over. She was lucky. Her brother in law lost most of his arm muscle from the same accident. I can't imagine......Poor kid, and I feel bad for the father too. I can't imagine....