A few years ago i fell out of the boat. In March. In 46 degree water. It was windy and I got off the trolling motor for a second while I grabbed a different rod and the wind blew me sideways and over the sides I went. It is a strange feeling looking up and seeing the bottom of your boat, several feet over your head. On a positive note, I was wearing Frog Toggs, which are kind of loose and puffy. When I went over they had enough air in them that I shot straight back up to the surface. Then adrenaline kicked in and 3 strokes later I was hanging on the side of my boat. When I first got the boat I practiced getting back into the boat (in the summertime, in 86 degree water) so I knew how to get back into the boat.
The moral of the story is that when I got home I pulled out the Bass Pro catalog and immediately ordered an auto inflating PFD. I've since upgraded to a hydrostatic type. It was a wake up call and should you fish by yourself alot like I do, you probably ought to get one.