I didnt learn how to swim until I was around 12. Still not a good swimmer at all, and I avoid going underwater when I can't touch a surface.

Went off a high-dive when I was 7 years old at a community pool. Cant remember if I was dared to or something similar. Ending up touching the bottom of the pool at around 12feet underwater. It was so long ago I have no idea how long I was under, but I remember clawing and struggling, out of air, up to the surface, then panicking and flailing to get to the side of the pool where I could climb out. Lifeguard was standing at the side asking if I was alright. I shrugged him off and went and sat down for a while.

Its still quite vivid in my memory all these years later. Dont know how close to death I was, but it sure felt like it at the time.