1. Why did it happen?
I wanted more time with a Pacific Electric Ray
2. What depth?
115'
3. What was your reaction?
I don't recall any reaction, it was a conscious choice.
4. What was your ascent rate?
50-60fpm
5. Did you have to go to the chamber?
no
6. General experience/thoughts/advice/anything else relevant
This was in 1979, as I recall. A 60' free ascent was mandatory for passing the SSI AOW course(Entry level cert at that time). As I worked at the LDS and assisted most classes, we regularly practiced free ascents from 80'. Embolism was the only concern we had at that time and that's easily prevented by maintaining an open airway. During checkouts with large classes, we might do as many as ten free ascents from 60' in a day. I now know why we were so exhausted after those days.
I also did a lot of free diving and could touch 80' on a breath, so I knew it wouldn't be an issue for me. I was diving an AT-PAC at the time and had it slung over one arm. Entered the water to retrieve a spear shaft and spotted the ray when I got to depth. It was just going to be an up and down to grab the shaft, but when I saw the ray, which were pretty rare at that time, I forgot the shaft and just watched the ray and my gauge. As the gauge drew down, I adjusted buoyancy, spit the reg and headed up.
Knowing what I know now, I'd never choose to do it again. But, I know I could. As I tell my students, if you get into the postition where a free ascent is your only option, you've screwed the pooch several times over and should consider another sport.
Boyle's law works.