Near the town of Monteagle, Tennessee, there's a place known as Foster Falls, where a waterfall goes over a sixty foot (or so) cliff into a large (and deep) pool of water that's well-suited to swimming. I first came to the place as part of a outdoor activities group, at the tender young age of sixteen. We'd hiked out wearing bathing suits, found the waterfall, and settled in for an afternoon of swimming. Someone mentioned jumping off the top of the waterfall, since the water was supposed to be deep enough.
The idea intrigued me, so I swam out to where the waterfall hit the pool. I made a note of where I was (just on the front edge of the falling water), then swam down to see how deep it was. I didn't actually find the bottom, which meant it was deep enough. Then I went back up and repeated the process a couple of more times, just to make sure that there weren't any hidden underwater rocks or suchlike waiting to snap my spine if I didn't land quite where I'd intended.
There's a path that leads up and around to the top of the waterfall, but after some consideration I decided that I wasn't going to do the whole sixty-foot drop. For various reasons, including the fact that I was there with a group, I decided to play it somewhat safer. So I got out of the water, and went up the rocky shore to the face of the cliff. The cliff, I'd noted earlier, had a nice little ledge that was just deep enough to offer a really good grip for my feet. (It was two or three inches wide, and the surface was actually tilted towards the cliff. On top of that, there was a second ledge running at about forehead level above it. This ledge was only wide enough for fingertips, but with the other ledge below it that would be fine.
So I put my toes in the wide ledge, and clung to the narrow one with my fingertips, and started making my way sideways until I was back out over the water. The plan was to get all the way out where I was even with the waterfall, and then jump backwards. I'd be able to kick off the rock hard enough to land pretty close to the spot I'd scouted earlier.
All of this was going fine until I reached a spot where the fingertip ledge began to climb. It went from being in front of my forehead to being over my head, but that was fine. Then it made another little diagonal ascent, at which point it was no longer possible to have my fingers on that ledge and my toes on the lower ledge. That was not fine.
So I stopped, and took a couple of deep breaths, and considered my options. For slightly complicated reasons involving how balance works, I decided it would be safer and more stable to be hanging down from the upper ledge (as opposed to having my feet safely on the wider bottom ledge, but with no good way to hold my torso against the rock). I thought through what I'd do if I fell. Then I took another breath and started off again, this time hanging by my fingertips from the upper ledge.
I got about five feet. The upper ledge finished its diagonal run, briefly became horizontal, and then turned back down and vanished completely. I had just run out of ledge to hang on. Well, okay, thought my sixteen-year-old self. I'll just go back until my feet can touch the bottom ledge, and try again that way. At which point I removed my left hand from the rock, and began shifting it back to my right so that I could, um, retrace my "steps".
It was at that precise moment that my right hand came off the rock as well, an event which let me clinging to nothing but empty air. I was about thirty feet up. I was not all the way out to the waterfall, so I didn't know how deep the water under me might be. Also, I knew that there was a ledge just a little bit below me, a nice wide ledge that could catch my feet and send me tumbling away from the rock in an uncontrolled back flip. So I did exactly what I'd decided to do if something like this happened, and kicked off from the rock. Now I really was hanging in empty air; gravity hadn't quite gotten a solid grip on me yet.
My heart gave this one tremendous contraction: Ka-THUD.
I started to fall.
My heart did it again: Ka-THUD.
I stuck with the plan. I got my knees bent, back a little curved, elbows tucked in, body loose. If I landed on anything solid I was probably going to break my legs anyway, but by God I was going to at least try to tuck and roll.
My heart did a third of those amazing, chest-absorbing contractions: Ka-THUD.
Someone screamed. Unbeknownst to me, the entire group had gotten out of the water and they were all watching me from the shore. I had time for my first coherent thought: You think you're scared?
Then my feet touched the water.
The moment I went under the surface I flung everything out: arms, legs, hands. Anything that would slow my descent.
I came to a stop just as my feet touched a rock on the bottom. I wasn't dead. So I kicked my way back up to surface and swam to shore.
Nobody talked much on the hike back. Not that I remember, anyway.
Edited to add: Huh. Apparently I wrote this event up once before. Well, if you want to look at two different retellings of the same incident, there it is. Might be interesting from a writing/storytelling perspective.