Years ago I was full of spit and vinegar. Made a makeshift wooden frame to mount a fiberglass chair in my 12' aluminum V-hull. All I had to do was slide the wooden frame with seat over top the fixed boat seat and I could rest my back on the fiberglass seat while catching spring time crappies. A little electric motor powered me across the lake. It was cold enough I had to wear a snow suit over my clothes (including long johns) to fight of the chill of the still winter winds. I went to a far shore and began my first drift, letting the wind push me across the lake. I hadn't gone very far, drifting sideways, when the boat hit a stump in the water. Within a millisecond the boat rolled back, dumping me and the seat into the water. I just "rolled" out. Seconds after hitting the water I sank. I could feel the water being absorbed by the snow suit and could see the boat floating above my head, getting further and further away. My insulated boots finally hit bottom (I'm guessing 10 feet) and my first thought was from my boy scout training. Stoop down, and then push with your legs! I shot through the water and was able to reach up and grab the stern of the boat, then pull myself up to gasp for air. As cold as the water was, it was truly difficult to get that lung full of air. The shore was about 35 yards away, but the wind was pushing me away. I struggled to swim to the shore pulling the boat, when a man in a canoe sped to my rescue. He grabbed the bow rope and pulled me to shore. From there I began bailing and realized my battery was dead and I was truly freezing. Thankfully a man was in mid lake with a motor boat and both the man in the canoe and I hailed him over. I bailed enough to ride in the boat and he pulled me to the ramp. Soaking wet I loaded the boat, and made it to a little liquor store up the road. The clerk acted like he had never seen a soaking wet man undress by his pot bellied stove before. The bottle of brandy probably didn't help, but I didn't care. I don't think I warmed up to normal for a week.
I tell you that to tell you this. When out on the water, pool, pond, lake, bay, or ocean, wear a life jacket. Stuff really happens quick out there.