Gosh, as a kid, at the public pool, which was an Olympic sized pool, I challenged my self to crawl along one of the black line at the bottom of the pool…they used the pool for high school swim meets, and the black lines delineated the lanes. So I did. To get to the bottom, and hang out there, you have to empty your lungs of some air, so you’ll sink.
I alligator crawled along that line, on half air,even when it dropped off the shelf to the deep end, at which point I had to let out more air, to about half way along the bottom of the deep end before I gave it up and used the last of my air to get to the top. Popped up gasping and proud.
We regularly threw small shit that would sink in to the deep end of the pool, and we’d have to do rescue dives for it….when the life guards weren’t looking.
I easily mastered swimming the length of the pool from one end to the other, lengthwise, on one breath. But…I’d been practicing holding my breath since I was 5 because…you know.