Three dead and one in recompression chamber in Italy, Tuscany

[boulderjohn]

That looks like an O2 deco bottle on the dock - presumably being impounded as part of one of the dead/injured divers' gear? How do you get to the point where you're using 100% for deco diving and miss the part about analyzing your tanks for CO?

I have never seen a technical diver test tanks for CO.

 

[DandyDon]

I have never seen a technical diver test tanks for CO.

I don't know if I've ever seen a tech diver in preparation, but it has seemed that most experienced divers tend to lack appreciation for how common the risk is - thinking that a dependable tank filler is enough. Affordable technology making tank testing viable is a fairly recent development, so there's insufficient exposure experiences to expose the risks.

 

[boulderjohn]

I don't know if I've ever seen a tech diver in preparation, but it has seemed that most experienced divers tend to lack appreciation for how common the risk is - thinking that a dependable tank filler is enough. Affordable technology making tank testing viable is a fairly recent development, so there's insufficient exposure experiences to expose the risks.

It is also surprisingly difficult to convince people that this is a risk worth worrying about. The odds are very much in your favor, and a lot of people figure that is good enough for them. As you suggest, that thinking is slowly changing.

As for technical divers, the overwhelming majority of fill shops do not have the ability to make the gases they need, so they usually get them from shops that are beyond the norm in terms of care in filling, using more thoroughly filtered air than typical shops use. Here in Colorado, we have almost no shops that have that capacity on a regular basis. I have made my own fills for the most part.

That is no guarantee by any means. The death of a cave diver in Cozumel a few years ago was believed to have been from CO the last I heard.

 

[Dr. Lecter]

I have never seen a technical diver test tanks for CO.

Weird. I don't dive a bottle, be it deco, stage, back gas, bailout, CCR dil or even 100% O2...without personally confirming its O2 content and that it's not carrying CO. I know at least some of the guys I dive with regularly are similarly anal about analyzing for CO. It may have to do with the fact that we're blending all our own gasses, rather than relying on a monkey at a shop and assuming they must have done it right because they're the experts.

Conversely, think of how many divers spend $$$ on a helium analyzer. Helium content...meh, nailing that exactly seems to be relatively unimportant...especially given how many people lie to their computers about He % anyway. Not breathing an odorless gas that can kill me in the same manner as hypoxia? Seems pretty important, and a lot cheaper to analyze for than helium.

 

[raftingtigger]

Got my Sensorcon CO monitor today. Very professional looking and seems well built. The scuba version comes with both a DIN and Yoke adapter (the yoke connection is a standard DIN to Yoke adapter - so that is a bonus item). Cost was $169 USD + shipping, which seems very reasonable. It has a 180 day countdown timer to remind the user to get it recalibrated. It looks like the user can do the recalibration, or they can send it in. The sales rep said the sensor is generally good for more than 2 years, often much longer. It is a replaceable part (about $100 USD currently). The monitor is Sensorcon's standard Inspector version, so it can be used for more than just scuba gases.

I tested all my tanks and momentarily had a concern. First tank I tested bounced from 0 ppm to 5 ppm then settled to a nice 0 ppm. Seems my garage, where the tanks are stored, has a CO reading of about 5 ppm. What I was getting was the CO in the garage before the tubing was cleared by the tank gases. I'm happy to report all my tanks have 0 ppm CO. All in all that showed the meter does read CO, and my tanks are clean.

 

[boulderjohn]

Weird. I don't dive a bottle, be it deco, stage, back gas, bailout, CCR dil or even 100% O2...without personally confirming its O2 content and that it's not carrying CO. I know at least some of the guys I dive with regularly are similarly anal about analyzing for CO.

I am not saying that testing for CO is not a good idea. I am saying that I have never seen it done among the people with whom I have dived. It is not discussed as an important step in the technical training documents I have seen (although it does get mentioned in some places). It should therefore not be surprising that it was not done in this case.

 

[Dr. Lecter]

I am not saying that testing for CO is not a good idea. I am saying that I have never seen it done among the people with whom I have dived. It is not discussed as an important step in the technical training documents I have seen (although it does get mentioned in some places). It should therefore not be surprising that it was not done in this case.

I think we'll have to agree to disagree about what's surprising in light of what's taught. The whole point of technical training is to focus the diver on thinking for and taking responsibility for themselves, and mitigating known risks when possible. It shouldn't need to be hammered home further in a special section on why CO analysis is a good idea: a word to the wise is enough.

That said, if your instructor(s) never bothered to analyze a tank for CO during whatever training(s) you went through, I suppose you may not put 2 and 2 together. But I do think it's surprising that supposedly risk-adverse, technically trained divers can know about CO, know about the importance of gas analysis, invest huge money in gear (including for gas analysis)...and still not check for something that has a low but never 0% chance of occurance versus a relatively large magnitude of potential harm.

 

[haslamhoff]

After following this thread I may not be the only one who is sold on adding a CO analyzer to their setup. Even here in Canada where I'd say the dive shops are pretty strict and regimented in their practices, I've had funky tasting air and a refusal by the shop that filled it to acknowledge the possibility of a problem (and yes, I know CO contamination wouldn't cause air to taste funky...)

Any interest/possibility/benefit of a group buy?

Time to start a revolution?

 

[boulderjohn]

(and yes, I know CO contamination wouldn't cause air to taste funky...)

Many times (but not always) the source of the CO will include other contaminants that will taste funky.

 

[undrwater]

...and interesting that many shops and boats appear to take it personally when one brings something up about bad air.