A FB friend posted his brother died today in Ginnie Springs

[boulderjohn]

That's probably a good guess on the air tank analysis rate. What do you guess the incident rate is on air tanks that contain some type of mixed gas by mistake? My guess is that it's less than your analysis rate, but I have never seen any mishap statistics to support any conclusion about the actual risk of getting a blend in an air tank. Most of the anecdotal data is related to blending errors (wanted 32%, got 29%), not diving an air tank but got O2 by mistake.

The question for the typical OW recreational diver (who probably doesn't own his own analyzer) is what the risk of an inadvertent EANx mix really means to his safety. A recreational dive in the air NDL range is not likely to be endangered by an accidental one-off use of a 32% or 36% blend marked as air. The chances of a rich deco mix or 100% O2 ending up in an OW rental air tank are pretty remote. Can you honestly say that the risk is significant enough to the predominant population of OW recreational divers to warrant having everyone go out and drop $300 on an O2 analyzer? Seems like an over reaction to me.

Are you talking to me? Or are you responding to someone else?

You quoted my post, but I can't see any relationship to what I wrote. In fact, everything you say to refute me is in total agreement with what I wrote.

 

[gianaameri]

I think the lesson to be learned from the Carlos fatality is about analysing the gas as a Team.

Had the Team on the fatal day analysed the gas as a Team, then the fatality would not have happened.

This is of particular importance where gas is planned to be shared in the Team (i.e. for training, for S-drill, or in an emergency).

I pointed this out in another forum and everybody went up in arms, but it is precisely what the NACD has put forward in a recent advisory following Carlos' death:

NACD Gas Analysis Advisory

The recent death of a cave diver highlights the necessity to review some critical procedures that we should be doing before all dives – gas analysis. A couple of years ago there was a cave diver death in Cozumel that resulted from breathing high carbon monoxide content in a cylinder. This created quite a commotion that caused the sales of CO analyzers to jump quite a bit. These days it’s not uncommon to see divers analyzing their cylinders for CO during the pre-dive process. However, even with that awareness it is a bit surprising that there are still divers that do not analyze all cylinders for oxygen content. While the NACD does not have courses for mixed gas procedures diving at this time, all NACD instructors should be emphasizing the need for gas analysis during the pre-dive process.

Divers should re-analyze all cylinders to be used on a dive at the site during the pre-dive process and make sure the cylinders are properly labeled with oxygen content, helium content (if any helium in the blend), and MOD. This should occur even if the cylinders were personally filled by the diver. Each and every cylinder should be analyzed and clearly labeled, even if there is an isolator connecting the cylinders, and regardless what gas is believed to be in the cylinder.

While it is understood that not everyone may own enough cylinders to permanently mark them with content and MOD, cylinders being used for 100% oxygen should be permanently marked and only used for 100% oxygen. However, permanent markings do not substitute for additional labeling. Even permanently marked cylinders need to be analyzed and labeled with content and MOD to show confirmation of the contents. There should never be any confusion about labeling. It should be clear and concise to anyone who looks at it.

Finally, there is some controversy over whether gas analysis should be an individual responsibility or a team responsibility. All divers with mixed gas training of any kind have been instructed that all gas should personally be analyzed prior to every dive. Almost every dive training class emphasizes gas sharing with teammates. With that, there is always the potential for a diver to be breathing from a teammate’s cylinders. Gas analysis and confirmation should be a team project during the pre-dive process.

The lessons to take away from this:

1. Analyze every cylinder, whether you think it is filled with air, Nitrox, Trimix, or Oxygen,
2. Label every cylinder with gas content and MOD
3. Remove all old, Oxygen, Nitrox, and Custom Mix labels if the cylinder is to be repurposed.
4. Make gas analysis a team project.

If you are unfamiliar with or out of practice with analyzing gas contact any NACD instructor and request a gas analysis refresher. If you do not have an NACD instructor nearby contact the training committee and we will provide you with an instructor who can help you.

Gas analysis is not an optional activity. Your life depends upon it.

Rob Neto
NACD International Training Director
NACD International Safety Officer

 

[gianaameri]

In another forum they made the thread on the Carlos accident disappear twice and all forums have the same group of people engaging in disparaging remarks and the usual aggressive tactics to confuse the core issues, namely:

1. Whatever the circumstances, Team Gas Analysis (as suggested by the NACD) would have prevented the fatality.
2. There is no evidence to date to support the allegation that Çarlos took (or intended to take) from Canada to Florida a tank filled with Air for the fatal dive. The tank was marked O2 and actually contained the marked gas. No tank was mismarked as instead happened in the Carl Spencer Britannic expedition fatality (Carl Spencer had brought a bottle of mismarked gas from home and it made it into the water for the Britannic Expedition Team Dive).

Sent from my HTC Desire C using Tapatalk 4

 

[shoredivr]

The NACD guidelines seem reasonable to me.

 

[gianaameri]

CDF had deleted the Carlos thread in the first instance and none is currently available for people to view at the moment (it says "Private").

Is there an open link to that thread for everybody to see what was written there, or may we continue the discussion here?

Personally, I have nothing further to add other than what I already posted.

 

[Dive Bug Bit Me]

CDF had deleted the Carlos thread in the first instance and none is currently available for people to view at the moment (it says "Private").

Is there an open link to that thread for everybody to see what was written there, or may we continue the discussion here?

Personally, I have nothing further to add other than what I already posted.

Actually I've just entertained myself for a good while on the show that was put on in CDF. The thread is there. Some time after the first few posts, that thread became pointless other than for cheap entertainment. Lets not try that again.

 

[gianaameri]

Actually I've just entertained myself for a good while on the show that was put on in CDF. The thread is there. Some time after the first few posts, that thread became pointless other than for cheap entertainment. Lets not try that again.

I agree it became quite pointless, mainly due to the lack of understanding of safe cave diving procedures by some of the participants.

The key and relevant points from that thread I have posted here.

I felt it was quite important that the NACD new guidelines following the Carlos fatality were shared as broadly as possible in the diving community.

NACD is right and a better and safer approach to risk mitigation.

 

[gianaameri]

Let us make it public here as the third relevant point to the Carlos incident.

Whilst it would have been sensible for him to bring some O2 for deco, personally, I find it odd that he is alleged to have brought from Canada a bottle of Air for a 30 meter cave dive.

 

[MMM]

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A ScubaBoard Staff Message...

The off topic discussion about CO risk has been moved to a new thread which may be found here: http://www.scubaboard.com/forums/ba...-risk-co-versus-incorrect-o2-tank-levels.html Also, a couple of snarky off-topic comments have been deleted. Please stay on topic and respect the special rules of this particular forum. Marg, SB Senior Moderator

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[gianaameri]

What I find odd is that Carlos allegedly carried from Canada an Alu80 bottle of Air (marked as O2...), when he also carried back-mount bottles of N30.

Air is cheap and it would have been easy enough for him if he wanted more gas to empty the Alu80 and fill it with the same gas he had in his back-mount (i.e. N30 which was quite suitable for the diving he intended to do).

Instead, he had an O2 bottle actually filled with O2 which we know he breathed at depth.

---------- Post added August 26th, 2013 at 02:58 PM ----------