The biggest hazard (if that's what you want to call it) I've seen at quarries like this, is the cold waters at depth & regulator freeze- ups. I frequently dive at Pennyroyal in KY. Below 60 ft it is 42 degrees year round, I would assume the other quarries in the region are similar. I have been there several times when there has been an incident. To date, the incidents I've seen turn out well in the end. Never a case of DCI or a fatality. The staff reacted quickly & got the divers out of the water & on oxygen ASAP. Only 1 or 2 have had to go to the hospital,... just for observation & did fine. The biggest culprits of these incidents is ill equipped, untrained or ill prepared divers. I've seen 1 diver who had a new drysuit on & didn't know how to control it come to the surface much too fast, I've seen a diver who had a pony bottle have a free flow, not know how to use it, freak out during the free flow & bolt to the surface. I had a free flow of my secondary regulator, last year at Pennyroyal, at 95 ft. I was wearing doubles & in the middle of a primary valve shut down drill. Having trouble reaching the valves because of the cold (thick gloves & stiffness) & 1 hand tied up holding the regulator to breathe from, I was able to breathe off of the free flowing regulator & make a decent ascent (minus the safety stop). My tanks were mostly drained by then, but I was in good shape. I have over 200 dives at this quarry & I would say that 1/2 of them are deep dives, that was my first ever free flow. I'm glad my IT/IC went over breathing a free flowing regulator just a couple weeks before. I hadn't done it since OW. The refresher probably saved my life in that event. That cold water is not to messed around with, but the risks can be dealt with, through proper training & equipment, in that order. As was mentioned above, the biggest problem with incidents at these quarries is divers who are not trained or equipped to deal with these "what if's".
