Posted 24 November 2011 - 09:53 PM
Alright, I went back & checked posts carefully. There is a lot of speculation on SubaBoard, & sometimes tough to filter through. Here is what I've got; one confirmed case of CO poisoning on Cozumel - a Cave diver, diving with a team that was mapping underground cave system, died October 16, 2011. Autopsy confirmed lethal levels of carboxyhemoglobin (formed when Carbon Monoxide binds with hemoglobin, blocking uptake of oxygen), and tank tests showed CO levels well above legal limit. He was diving a Nitrox fill; other divers in his group were unaffected, all were diving with air fills, all other tanks were within safe CO levels. Two other fatalities recently: One suspected of being a heart attack, but no autopsy performed; One a case of drowning, but no explanation why a 60 year old experienced diver in good health would leave her dive group to surface, not make it the surface, and drown (perhaps another cause resulted in a siezure, but no autopsy report, no report that tank was tested. So, maybe it was only one in three that was definitely CO poisoning. We won't know unless & until the tanks are tested, and the test results are released, whether CO was a contributing cause in either of the other 2 cases - maybe it triggered the heart attack, maybe it was just the stress of diving. And maybe CO caused disorientation of the other diver who died on the 21st, or maybe it was something entirely different. There seems to be a real reluctance on Cozumel to release hard facts. There was a situation 2 years ago in which three divers, all with the same Dive Op, got very sick with CO poisoning, but no fatalities. That Dive Op was using its own compressor and had a bad filter on its intake. I understand that there is now an in-line CO analyzer at the Meridiano fill station (which is a good start), which fills most, but not all, tanks used on Cozumel. But that analyzer is only as good as the people who install it, maintain it, calibrate it, and (hopefully) continuously monitor it. Even if the risks of a contaminated tank are minute, the results for the one in ten thousand divers who might get a bad fill are disastrous. I'm buying the CO Analyzer & using it on every tank I dive.