I have had one failure like this since 72, and it was with an AtPac on the Hole in the Wall dive( at 145 deep on a spearfishing dive). It was a high current day back around 1988, and everyone was diving extra weight so we could fall onto the ledge fast enough on our descent, not to be blown off 45 degrees going offshore, with the outgoing current flow running over 3-4 mph.
I remember about 8 minutes into the dive, bumping into the bottom--too heavy, right after shooting and stringing a fish.... and then blowing air into my AtPack with the inflator...and nothing happened. I could not see the leak, or what the problem was.... I just assumed I had a catastrophic leak or failure in the wing. What had happened( I found out later) was that the hose connection where it connects to the wing, had pulled out, and all the air had left the wing--and none could get into it.
I was ridiculously heavy, in winter weight wetsuit, at 145 feet, with maybe 1500 psi left. All the other spearfisherman were chasing their prey or heading up to the surface, and no one connected with me visually to see the problem....
At least 25 pounds heavy, I began a full power swim upward, using the Ankle brace style Fara Fins ( huge thrust at full power, zero efficiency and low thrust at medium or slow kick ).
I was a top cycling racer back then, and got the heavy load up to about 20 feet from the surface, before the anaerobic level of the 100% workload began to shut down my propulsion capabilities.
I had my double barrel monster gun in one hand, and big hog snapper on a stringer still in my other hand... I was a caricature of foolishness in those days---I would not surface and let anyone know that I had been afraid of drowning and been forced to drop gun, fish or weight belt....so, I kept pushing as hard as I could to get to the surface. The next 20 feet took far longer than the first 120, but finally I was within 3 feet of the surface, just as my legs were turning to jelly from high lactic acid. Just as they were about to shut down, the Platform which hung down 2 feet into the water from Frank's dive boat was visible directly over my head--and had stopped right there--obviously Frank had seen my bubbles, and had moved in to pick me up( he would find divers by bubbles all the time)...I made my final sprint, and my hand caught the bottom of the ladder.....I grabbed on firmly, my legs now exhausted, went limp, and I hung on the ladder about 20 more seconds to get my breath.....then slowly pulled myself up onto the platform--threw the gun up and handed the fish up....
I was silent regarding the issue I had had until I recovered about 5 minutes later. I was just sitting on the bench, still attached to the tank. So finally I get out of the AtPac, and see the hose separation. I shared the failure of the Atpac with my friends, but did not really relay the severity of the issue.
Had the boat not been right over my head, I would hope that my choice would then to have been the dropping of the 7 pound gun, and the fish, and the release of the weight belt...and that would have been sufficient.....Stil, the atpac had it's own weighting that did not drop out of it, and I am not certain that I would have been positive at that point without dumping the tank and then free ascending---with the maximal breathing rate of the emergency effort, this would have been a bad proposition.
Of course, the moral(s) of the story would be : dive with a buddy, even when spearfishing; don't be ridiculously overweighted; Don't use a tank that you can't easily swim up if you have a wing failure; Don't be a macho jerk;
Don't be hesitant to dump gear you like, if you think your life may be at stake----don't lie to yourself about whether your life is at stake ....
Anyway, this was a lesson I leaned well, and many years later after George and Bill got me to be DIR, I became particularly vocal about how much negative weight is acceptable for a diver to use--the concept we discuss today as diving a "balanced rig".
