I was in the very front of a crowded wave pool (most of the people were sitting in tubes) where the waves are the highest, because there was only one other person up there and I wanted my own space. Now, there wasn't anything to hang on to, and I was only 11 years old and 5'5", so I had to tread to keep my head above the water. The waves are getting higher and higher, and I'm getting tired every passing second from treading for so long (I'd been in there for ~20 minutes) and a giant wave washed right over me in the middle of me taking a breath, washing me under the wall of tubes behing me. That shit felt impossible to get out of, and my heart was beating so fast when I resurfaced. I'm glad I didn't drown, but it was a terrifying experience.