captain
Contributor
Footslogger:=======================================
All excellent points ...but in the interest of full disclosure, I actually was the OOA diver once (and that's all it took ...ONCE). It was in the olden days of the J valve with the pull wire along side the tank and we didn't dive with octopus rigs or spare-air back then. Somehow between the surface and the bottom the valve had gotten activated (probably on entry). After a bit of diving at 100' + I checked my SPG and it was at (or about) 500 PSI so I decided to pull the wire and realized that it had already been activated. A couple breaths later I was pretty much OOA and had to make a "whistling" ascent. I was wearing an old CO2 cartridge horse collar (BCD's were pretty new back then) and it was empty so toking off the inflator valve wasn't an option. I broke the surface like a Trident Sub on a full combat ascent ...and lived to tell the story.
Where was my buddy, you may ask ?? He had signalled to me that he was headed up about a minute or two before I realized my situation. I could see him above me as I started upwards but by then I was hell bent to get to the surface and reaching him and asking him to donate his primary wasn't my first thought.
This may not be totally on-topic but the point is (and someone mentioned this in an earlier post) that sometimes YOU are the OOA diver and it is due to cirmcumstances beyond your control (well ...almost). FWIW ...I never dove a J valve set-up again and I now head back to the boat when the gauge reads 1000 PSI.
This was about 30 years ago and I had well over 200 dives without incident.
I am not sure if I would consider 500 psi at 100 feet exactly an OOA emergency. I have made normal ascents from 80 feet with 200 psi.