That is scary and freaky. Although I always stop a lot and look around whenever I'm in the water it really is on the boater to avoid that situation.

I once had my runabout on a lake looking for a fishing hole. I went into a small inlet that had a dock on one side and I noticed one kid on the dock and another snorkeling on the other end of the dock. By the time I got into shallow water and had to turn around the kid in the water had made it to the other end of the dock. I was looking for him but didn't see him. As we were turning luckily I saw him underwater pushing off of the dock as my stern was swinging straight for him. He was probably 25 feet away and within 5 seconds we were about 10 feet apart. Luckily I stopped and he noticed the prop and popped up. I've thought about that one a lot over the years. I'm pretty sure I'd have been at fault if we hit him but even if somehow it had been deemed to be no one's fault it would have stuck with me for life. I'm a much better boater from that experience - now I expect the unexpected to happen.