Use your CO analyzers

[Mossman]

This is mainly for Mossman, since he like to ask hypothetical questions too, but it would be interesting to hear how others would act;

Let's say you're on the boat ride to Punta Sur, when you realize that that guy checking his tank for CO, O2, and rat turds- is none other than the DandyDon.
-You & the dive op. didn't bring any analyzer.
-He gets readings of 20ppm, 21%, and 0 from his tank.
What would you do?

Great hypothetical question DSR-3, I might suggest that Mossman could take that tank, and he check another. Perhaps mine, Just for laughs.

I wouldn't hesitate to dive my own tank, but I'm sure not diving his. Luck of the draw.

20 ppm wouldn't bother me. That's only twice the legal limit.

 

[theduckguru]

Somebody contact Nate Silver.  What are the odds of a contaminated fill, Don and Mossman on the same boat the same day on a ride to Punta Sur?

This is mainly for Mossman, since he like to ask hypothetical questions too, but it would be interesting to hear how others would act;

Let's say you're on the boat ride to Punta Sur, when you realize that that guy checking his tank for CO, O2, and rat turds- is none other than the DandyDon.
-You & the dive op. didn't bring any analyzer.
-He gets readings of 20ppm, 21%, and 0 from his tank.
What would you do?

 

[ggunn]

You are taking your life in your hands. However whether you choose to do anything about it is strictly your choice.

There is no "false evidence." Tanks sometimes contain CO. People sometimes dive these tanks and die. I see no slight-of-hand or deceit here. People do die from diving contaminated tanks.

Au contraire. Near the beginning of this thread there was a statement that there had recently been a confirmed death of a diver from CO poisoning. That was a false statement; in fact, although a diver did die, that it was due to CO poisoning was only the inexpert opinion of a friend of the diver. There was also the opinion stated as fact that other unexplained diver deaths were due to CO poisoning. I ask you, if all these stories were the smoking gun of CO poisoning, why is it that it has always happened to customers and not DM's who dive several times a day, nearly 365 days a year?

We play that same Russian roulette game every time we get on an airplane, even though we know that in the event of a crash (and crashes do happen), we have very little chance of survival. It is not an abandonment of risk management to not wear a parachute every time we fly.

I'll just add that if I were a cave diver, diving in conditions in which calling a dive and heading for the surface were not an option, I would rigorously analyze every aspect of my air, including CO content.

 

[flots am]

But can you give me definitive proof that a recreational diver has died from CO on a dive in Cozumel recently?

In Cozumel? Who cares where they died? CO can show up anywhere. Cozumel isn't exempt.

In fact, given the way dead tourists are handled in Cozumel, it's unlikely you could find proof that anybody was killed by anything in particular. It's bad for business and tends to "go away" quickly.

And yes, you can bet that when I dive in a place with where the tanks magically show up at the boat, with no VIP sticker, no recent hydro stamp and no indication who owns them or who filled them, I'm going to check the gas.

---------- Post added March 15th, 2013 at 09:27 AM ----------

I ask you, if all these stories were the smoking gun of CO poisoning, why is it that it has always happened to customers and not DM's who dive several times a day, nearly 365 days a year?

Saying there have been no proven deaths from CO in Cozumel is like Galileo saying he hasn't detected neutron stars. It's correct, but doesn't mean they don't exist. CO poisoning in tourist locations is often written off as a heart attack or drowning, which Coz seems to see quite frequently.

DMs are typically in better shape than tourists, use less air, breathe less, are younger, are more likely to go home and complain about a headache than make a stink about air quality.

flots.

 

[Ron Lee]

Saying there have been no proven deaths from CO in Cozumel is like Galileo saying he hasn't detected neutron stars. It's correct, but doesn't mean they don't exist. CO poisoning in tourist locations is often written off as a heart attack or drowning, which Coz seems to see quite frequently.

Again we get the unsubstantiated subtle suggestion that heart attacks and drownings in Cozumel are due to CO poisoning.

DMs are typically in better shape than tourists, use less air, breathe less, are younger, are more likely to go home and complain about a headache than make a stink about air quality.

I will accept as likely true your first four points but not that they will go home with a headache and not complain. That means that they are placing their job over the safety of their customers. I understand human nature but would not be certain that a dive shop manager/owner would fire a DM for notifying of the possibility of bad air. In most cases, dive shops are customers of a tank filling facility.

A real case of CO poisoning, even if it did not result in a fatality, would result in fewer scuba customers for a while.

 

[DandyDon]

This still going? Ok...

As I tried to say before, and was misunderstood by some, or I might not have stated it clearly - I'm not going back in a diligent search to establish which as it's more depends on reader's view I think: No one knows how often that cases of traveler's illness were really cases of subclinical CO hits, nor how many of the lost or drowned divers were really incapacitated by tank CO? You can pick any number between none and all and your guess is as good as any - for the island, the area, etc. The risks have simply not been well studied, some are just not aware, and some who are still don't want to. Besides, it'd be pretty hard to do such studies as the common practice for suspected tanks is to drain them, not publicize such. Even for compressors running inline monitors now, if they are monitored & maintained well, I doubt the owners are going to be interested in reporting their bad experiences.

I'll just add that if I were a cave diver, diving in conditions in which calling a dive and heading for the surface were not an option, I would rigorously analyze every aspect of my air, including CO content.

Well, I had thought the the cave diving community would be more likely already testing for tank CO simply because of their technical nature & approach to diving, but I learned that was not the case. They were generally as far behind as most of us on this, altho seemingly more interested in changing. I spent some time on one of their forums after a cave death on Coz and that was my impression anyway. That one was previously blamed on CO, more recently other factors have been made known to me, but the team agreed that that they just did not want to discuss the details in public.

Heading for the surface works well for LOA/OOA situations, but not so well for CO hits in part because of the way CO binds with blood and stays as previously explained. It didn't work for the 2 who died in Roatan a few years back, not for the Maldives bunch who were all very ill surfacing - 1 dying, not in the more recent Baja accident with 2 ill & 1 dead. It's worth a try and sometimes makes the difference so a cave diver would seem more at risk, but it can still fail.

I know you always dive with the same Op as you have for years, and I know them to be a fine Op to my limited experiences - but last I heard they were filling their own tanks. Do you know if they run inline CO monitors?

In Cozumel? Who cares where they died? CO can show up anywhere. Cozumel isn't exempt.

In fact, given the way dead tourists are handled in Cozumel, it's unlikely you could find proof that anybody was killed by anything in particular. It's bad for business and tends to "go away" quickly.

And yes, you can bet that when I dive in a place with where the tanks magically show up at the boat, with no VIP sticker, no recent hydro stamp and no indication who owns them or who filled them, I'm going to check the gas.

Saying there have been no proven deaths from CO in Cozumel is like Galileo saying he hasn't detected neutron stars. It's correct, but doesn't mean they don't exist. CO poisoning in tourist locations is often written off as a heart attack or drowning, which Coz seems to see quite frequently.

DMs are typically in better shape than tourists, use less air, breathe less, are younger, are more likely to go home and complain about a headache than make a stink about air quality.

flots.

I'd say that's a realistic appraisal. I don't know if the local hospital has the ability to test for carboxyhemoglobin (HbCO) in blood yet, but patient privacy rules would prevent us of knowing results anyway. Tank CO analyzers were non-existent on Coz is past years, but while that is changing - I don't think they have scuba police who show up immediately with ambulances to test tanks before they can get lost. It's just not going to happen. The DMs seem to have fared better than the tourists on the group hit at the Occidental Grand a few years ago. See http://www.scubaboard.com/forums/ne...ned/324039-carbon-monoxide-tanks-cozumel.html Whether tanks or blood was tested was never made public. A surprising statement excerpted from that report: "We learn that on the 10:30 am dive there were 2 incidents similar to our 2:00 pm dive, however, there was no mention of the problem or mention of stopping the dive or any concern. The only thing that they may have done to minimize the problem was there were two dive masters with us on the dive. But that may have exasperated the problem because instead of stopping the dive after the first diver went up – they continued the dive with the one dive master until the 2 other divers went unconscious." The hotel changed house Ops within a week tho.

Is Coz more dangerous than the rest of the Caribbean for CO risks? No, I don't think so at all. It's a risk anywhere. Some of us are keeping the testing & reporting pressure on at Coz more so maybe it's safer. I still don't agree with DAN's approach of gifting a few inline monitors to selected compressors in the area, but maybe they are being used right.

The bottom line is the only way to know about any tank, anywhere, is test it yourself. Past performances really are no guarantee, but your call...

 

[nimoh]

Heading for the surface works well for LOA/OOA situations, but not so well for CO hits in part because of the way CO binds with blood and stays as previously explained. It didn't work for the 2 who died in Roatan a few years back, not for the Maldives bunch who were all very ill surfacing - 1 dying, not in the more recent Baja accident with 2 ill & 1 dead. It's worth a try and sometimes makes the difference so a cave diver would seem more at risk, but it can still fail.

just to add to that, at depth with CO bound to hemoglobin, the higher partial pressure of oxygen in your breathing gas may be keeping you alive, and returning to a lower partial pressure might just do you in.

...this is my understanding, but I'm no expert, please someone correct me if I am wrong

 

[ggunn]

In Cozumel? Who cares where they died? CO can show up anywhere. Cozumel isn't exempt.

In fact, given the way dead tourists are handled in Cozumel, it's unlikely you could find proof that anybody was killed by anything in particular. It's bad for business and tends to "go away" quickly.

More conjecture stated as fact. How many dead tourists have you handled?

Saying there have been no proven deaths from CO in Cozumel is like Galileo saying he hasn't detected neutron stars. It's correct, but doesn't mean they don't exist.

No, it's not. We have a lot of evidence that neutron stars exist. We don't know that there have been any deaths from CO poisoning in Cozumel.

It's true that that we don't know that there have not been any deaths for CO poisoning there, but that in itself is not proof, or even evidence, that there have been. Neither is conjecture that such deaths have happened and have been passed off as something else.

I never said CO in dive tanks on Cozumel was impossible, only that I consider the risk to my own person (YMMV) to be low enough not to worry about, with a plan of action should I start to show symptoms. I know from personal experience that one gets to feeling VERY bad from CO poisoning long before death occurs. I believe that the odds of my encountering a high enough concentration of CO in a dive tank to render me dead or unconscious before I note symptoms and take countermeasures (abort the dive, surface, mark the tank for analysis) to be vanishingly small.

I am not speaking for anyone but myself, and my risk tolerance on this issue is mine and mine alone. Again, YMMV.

---------- Post added March 15th, 2013 at 05:34 PM ----------

I don't think that anyone's mind is going to be changed by any of this. Can we talk about something else?

 

[Angry Turtle]

---------- Post added March 15th, 2013 at 05:34 PM ----------

I don't think that anyone's mind is going to be changed by any of this. Can we talk about something else?

I think we can all agree this thread has exceeded its shelf life

 

[Johnoly]

just to add to that, at depth with CO bound to hemoglobin, the higher partial pressure of oxygen in your breathing gas may be keeping you alive,

Your sentence is kinda mixing 2 different events taking place. To keep it simple, at depth, it's easier for hemoglobin to release any "AVAILABLE" O2 molecules into the tissues because materials move from high tension(hemoglobin) to low tension (tissue) the easiest. But if you run out of O2 Molecules attached to hemoglobin, then 'just a few' is still 'too few' O2 molecules whether at depth or on the surface. So yes the transfer of O2 molecules is easier, but if you don't have any, then your tissues are still starved with not enough coming from the hemoglobin.

...and returning to a lower partial pressure might just do you in.

This quote is correct because not only have you starved the tissues, but by returning to a shallower depth, you've made it harder for the tissues to 'accept' any remaining O2 molecules that might be available. This is why even if you make it to dry land, you can still "suffocate" from lack of O2 Molecules cause they can't attach to the hemoglobin and even if they could, they can't easily transfer to the tissues because you are at surface pressure. Even at surface pressure, not every O2 molecule is "transferred" to your tissues. This is why when you exhale, your breathe still has some O2 in it.