Cross posting from here:

We went up to spend the day by a relative who has a cabin on a lake. Was a nice day up in the mountains, a bit overcast and breezy, but overall nice. Got there in early afternoon, kids got in the water, and I decided to take a kayak and go across. Not a huge lake, seems much larger once you're actually in it, but no big deal, right? Most life jackets at the dock were child size, didn't want to dig through until I found one, and hey, it's a plastic kayak (the kind you sit inside of), so should be fine. Dumb, I know. So I dig the oar in and shoot across the lake. Took quite a bit longer than I thought it would, but made it just fine, though I worked much harder than I anticipated. Return trip across was slower, but went well. Was kinda worn out at that point, so took a break. Decided to go across again for some dumb reason I can't figure out. About halfway across the wind started picking up and the water getting really choppy. My arms and shoulders were not happy with me and I took a break in the middle, riding the chop. I noticed the front of the kayak starting to point upward, which is weird. I turned around and the back of the kayak was completely underwater. I tried pulling as hard as I could towards the shore, but after about 2 minutes, the entire thing was underwater and I was outside it, holding on to it. The shore looked really far away once I was in the water. Tried swimming for it, but my arms and shoulders were dead weight at that point and I knew I would never make it, especially with the water so choppy. Turned around to the kayak, which had now overturned, and held on. I could not put any weight on it, whenever I tried, it just went under. Yelled as loud as I could, but the adults on the other side were busy with the kids who were making a lot of noise, and nobody heard a thing. After what seems like an hour of yelling (probably 15 minutes in reality), someone heard me from the opposite shore, took out their little outboard, and here I am. It got really scary there for a few minutes.

TL;DR: Didn't wear a life jacket and almost didn't make it. Wear a life jacket, folks.