I missed that...I don't get over to A/I much....clearly, not as much as I should.
I just went through my old emails to see how long I've had the CO analyzer-I got it in 2010, and if I recall correctly, I finally looked into it after there was a CO incident on the island, involving an OP that fills its own tanks; the story that was eventually posted suggested that a truck was left idling in the same vicinity as the compressor. No doubt there are others on the board who have more details and/or more accurate recall than I do, regarding this incident.
Anyway....I started testing in Sept. or Nov. 2010, and I do recall getting several tanks on that trip, and possibly the following trip (which would have been Feb 2011). There were some that were pretty high-ie 10-14 ppm. I would never dive that concentration, though physiologically, I probably could tolerate that. There are people who couldn't, and really, no one should take the risk. Keep in mind the partial pressure of the gas increases, the deeper you go...so 10 ppm at the surface is not what you will be breathing at 33, 66, or 99 feet.
Since those trips late 2010/early 2011, I have had only a few tanks that had more than 2-3 ppm. I dive a minimum of 70 tanks/year that are filled on the island, the vast majority coming from the central fill station-though I have been out a few times with ops that did not get there fills there.
I test every tank, every time. Other divers on the boat are sometimes curious and ask me about it-but never once did I get the impression that any one of them was actually concerned about CO in their tanks, and I have never once been asked by a diver to check their tank. I've never even had the impression that someone was hinting at it. This, after my explanation to the other diver(s) about the CO issue, illustrated with a few examples from my own professional experience dealing with anoxic brain injuries-including CO poisoning related. Would I do it if asked? Yes, if asked. It's up to each diver to find out about the risks of diving and make their own decisions, including whether or not to test, and what their own personal comfort level is regarding PPM of CO. I don't own that responsibility for others when I am out diving.
Why the lack of concern? I am guessing that it is because, statistically speaking, it is relatively unlikely to happen to any one specific individual. People that go to Coz to dive know that there are hundreds, and sometimes thousands, of divers in the water every day, and, as far as they know, "nothing bad happens". And most days, that's probably true. Also, they look at the DMs, most of whom have thousands of dives, and who have not had a CO incident, and figure their own chances are slim to none. And that's partially true-the "slim" part...not the "none".
There are people on this board who know a lot more about the various safety standards set by various occupational watch dogs, and standard in different countries-perhaps they will chime in.
That thread you posted, and the subsequent comments, are really interesting. As a point of clarity regarding the tank at Blue Angel that one of the posters declined to dive-I wonder if BA is still filling their own tanks? They were a few years ago. I have had a few similar experiences, one at BA, and a couple others, each with a different DM/shop. I have twice had a DM dive a tank I refused to dive-even when I asked them not to. I have also seen a DM-, and on a different occasion, with a different OP-a shop manager-simply take the tank I reported and casually set it "aside" right next to or among the other unused tanks. I saw no attempt to separate or identify the tank by number, or tag it.
I would NEVER count on any DM or any OP to actually pull a tank, much less investigate further. Some might, but I would not count on it. Over the years, several DMs have asked me about my CO analyzer-sometimes more than once-and it has been very clear in most cases that they either didn't understand the CO issue, and/or didn't care. Perhaps that would be my attitude if I had made thousands of dives without incident.
I also would NEVER count an a fill station to stop filling if their one of their CO monitor was down, nor would I count on a particular station to even have a CO monitor.
Testing takes moments. I haven't run into any protestations from DMs/shop managers over testing. It's really hard to imagine a DM getting that excited about you pulling out an analyzer-especially when many of them won't have any idea what you are doing.
Get on the boat. Put the bc on the tank. Wait until you are not idling at a dock or otherwise exposed to exhaust. Have the regs off the tanks shortly before you intend to test. Line em up and do it, just like for nitrox. And, of course, let the monitor equilibrate between tanks.
Industry wide results show a 3% failure rate, which is a small number - unless you get one of those.
