Cozumel Diving 2/26/12 - Had one tank read 12 ppm CO -

[jbtut]

I think the same reasoning that we use dive computers for is equally applicable to CO. I could trust the DM to dive a safe profile. They do it every day and 99.999% of the time, the guests don't get bent. I could probably dive with any reputable dive shop without a computer and never take a look at a table and never get bent just by trusting that the profile they take is safe.

I'm having a hard time distinguishing the basis for being willing to spend $300 on a dive computer, but not $175 to evaluate whether the air is safe. I simply don't know the numbers well enough to determine if DCS (on guided dives) is orders of magnitude greater than rist of co poisoning. Possibly you're not getting much safety for your $, I really don't know.


My goal wasn't to be alarmist at all. Just to note that I did find one tank on our trip that had a reading outside the limits for grade E compressed air out of a dozen tanks, one was outside the usual limits. If it were 120ppm rather than 12ppm, it would be a bigger deal.

 

[WOODMAN]

Why on earth would someone resist the idea of testing your tanks for CO? Granted, there are a lot of super cautious people out there who take precautions to a ridiculous and impractical level, where they actually interfere significantly with their activities, but that's really not what we are talking about here. In short, we are talking about a small meter which costs 100-200 bucks (peanuts for scuba gear, really) and which is readily stored in anyone's gear bag. The actual test takes only a few seconds (depending on the meter) and the results are clearly understandable to anyone with a lick of education on this subject. And if you think you are going to offend the dive operators, then maybe you are diving with the wrong people. When I got a moderately elevated reading on a tank at Reef House in Roatan, (the only time it has ever happened to me) the owner of the resort was right there and took the tank and vented it right in front of us to prevent it's use by anybody until it was flushed and refilled. He was more than grateful to know about it, and that is the typical attitude I have found when discussing this with other operators. Maybe it's a subject that you think is overhyped, and not really a problem, but the more people look into this, the more it seems to be showing up. So I guess it's your choice- use what they give you and hope it's okayraying:, or run a quick little test and know what you are dealing with. It's up to you... Woody

 

[Mossman]

I'm having a hard time distinguishing the basis for being willing to spend $300 on a dive computer, but not $175 to evaluate whether the air is safe. I simply don't know the numbers well enough to determine if DCS (on guided dives) is orders of magnitude greater than rist of co poisoning. Possibly you're not getting much safety for your $, I really don't know.

Your risk of getting bent while following your tables or dive computer (the "undeserved hit") is likely higher than your risk of getting CO poisoning from a tank.

However, your risk of getting bent while making up your own profiles without benefit of tables or computers will be far higher if you're diving below 50' or so. On the other hand, you could do practically all the diving you want without tables or computer if you simply stay shallower than 40'.

If all your diving is "follow the leader" doing two shallowish profiles a day, you're probably OK without a computer. Where I find a computer can be helpful regardless of the dive profile is in monitoring ascent rate (and my Suunto also reminds me to do deep stops which purportedly make me a happier camper).

 

[iluvcozumel]

I agree with Dandy Don......why in the world would you not test your air......Same reason you test your Nitrox....never take your life support system for granted. Those that don't believe in testing air probably don't get their unit serviced annually either. I understand trusting the air we get from a dive shop. But it only takes one tank with 12ppm and a dive to 100 ft and then you become a statistic. And most dive incidents are called a "drowning" because that is the most obvious cause of death....but why did the victim drown, unconsiousness from too much CO?

 

[Ron Lee]

.but why did the victim drown, unconsciousness from too much CO2?

CO = carbon monoxide

CO2 = carbon dioxide

 

[Mossman]

I agree with Dandy Don......why in the world would you not test your air......Same reason you test your Nitrox....never take your life support system for granted. Those that don't believe in testing air probably don't get their unit serviced annually either. I understand trusting the air we get from a dive shop. But it only takes one tank with 12ppm and a dive to 100 ft and then you become a statistic. And most dive incidents are called a "drowning" because that is the most obvious cause of death....but why did the victim drown, unconsiousness from too much CO2?

You're right. Every two years for me. Annual service is a yet another marketing scam.

There are lots of 100' dives in Cozumel going on each day. According to the posters here, lots of tanks test higher than 12 ppm. So where are the statistics?

 

[markmantei]

The reality is that we have NO reliable statistics on how good or bad our gas is because few divers are checking. The more divers are starting to check, the greater the frequency we are identifying issues. Forget the fact that divers are not even being tested in the event of a fatality, not everyone exposed to air with CO contamination will die. Often it may only result in sickness which once again can be either misdiagnosed or blamed on some other cause.

 

[Mossman]

The reality is that we have NO reliable statistics on how good or bad our gas is because few divers are checking. The more divers are starting to check, the greater the frequency we are identifying issues. Forget the fact that divers are not even being tested in the event of a fatality, not everyone exposed to air with CO contamination will die. Often it may only result in sickness which once again can be either misdiagnosed or blamed on some other cause.

So now it's not even a risk of death, just a risk of getting sick? Then I'll respect the advice to purchase and use a CO analyzer with the same weight that I apply the advice to not eat salads or undercooked meats and fish in Mexico.

 

[stevep4444]

This is an interesting article from the similar Coz thread discussing this issue. | Medicine & Science - take care for your health So if I understand correctly, the approximate level of 3000 ppm of CO would be knock a diver into uncoscienceness. I'm guessing this is not an absolute number but approximate. Should you get a bad tank with 20 ppm of CO and dive to 100 ft I am wondering what noticeable effects ,if any,you would experience post dive. At depth you would be exposed to 80 ppm. If a smoker has about 400 ppm of CO at the surface,I would guess you would feel much better after the dive than he/she would even if they had a tank with 0 ppm. Where is my logic flawed here?

 

[iluvcozumel]

You're right. Every two years for me. Annual service is a yet another marketing scam.

There are lots of 100' dives in Cozumel going on each day. According to the posters here, lots of tanks test higher than 12 ppm. So where are the statistics?

True, there are probably 1000's of dives going on to 100' and deeper, and no one dies. And yes, it will take much more than 12ppm, my point was CO present in a tank is a red flag, so why take the risk when the technology is available and relatively inexpensive? It is all personal choice, I know. And as far as getting your annual service, I have heard that some operators are beginning to require proof of a service in the past year on your personal equipment or you don't dive on it. A regulator is a life support system, I don't feel like taking a chance.