One issue is that until only a few years ago, fresh water electrocution was miss diagnosed as drowning. It was only 10 years ago that we realized that hundreds of fresh water drowning cases were in fact fresh water electrocution. Turns out this is a much bigger problem than the general public currently understands.
If you see a diver sit on the dock and put his legs in first to see if he feels any current than he is probably educated on the issue. If he just jumps in then maybe he is in need of education on this subject.