Question NITROX (in less than 40 foot of water)

[steinbil]

Now that he knows it’s 32% and hard bottom is 40 feet, I can’t see how it would be dangerous to dive it as nitrox 32% if he has computer that has ability. He can’t have hyperoxia because of so shallow hard bottom. Can’t really do anything wrong vs air even if you don’t know anything about nitrox diving. Other places that are deeper, it’s different thing, but his dive site I can’t see problem.

If, as you say, other dive sites might be a problem, then there is the potential issue of normalization of deviance. By diving the gas he's not certified for and not having an issue, it might make it more likely he will do the same thing again in a different environment without knowing why that would be different - you don't know what you don't know.

This is not a dig at OP in any way, who seems very reasonable and open to listening to others. But normalization of deviance is real and a normal part of human psyche. I know divers who have accidentally gone into deco a few times, and now do it on purpose without training.

 

[CT-Rich]

If, as you say, other dive sites might be a problem, then there is the potential issue of normalization of deviance. By diving the gas he's not certified for and not having an issue, it might make it more likely he will do the same thing again in a different environment without knowing why that would be different - you don't know what you don't know.

This is not a dig at OP in any way, who seems very reasonable and open to listening to others. But normalization of deviance is real and a normal part of human psyche. I know divers who have accidentally gone into deco a few times, and now do it on purpose without training.

He is ASKING if this would be safe. He is not ASSUMING it is safe. If I come hope and find a pot of soup on the stove, and I eat it, their is risk involved. If I ask how long it has been sitting out, before I eat it, I am safely mitigating the inherent risk of eating soup of unknown origin.

He knows what gas they are supposed to be and he is not going to be able to replace them without getting nitrox certified (truly one of easiest certs to obtain). Should he waste $25 of air? I don't think this is a massive breach of protocol or even the normalization of deviance. I don't think this going to result in solo cave penetration on an aluminum 80 with spilt fins and a snorkel.

 

[steinbil]

He is ASKING if this would be safe. He is not ASSUMING it is safe. If I come hope and find a pot of soup on the stove, and I eat it, their is risk involved. If I ask how long it has been sitting out, before I eat it, I am safely mitigating the inherent risk of eating soup of unknown origin.

He knows what gas they are supposed to be and he is not going to be able to replace them without getting nitrox certified (truly one of easiest certs to obtain). Should he waste $25 of air? I don't think this is a massive breach of protocol or even the normalization of deviance. I don't think this going to result in solo cave penetration on an aluminum 80 with spilt fins and a snorkel.

I'm not saying this is a massive breach, or even that I advise OP not to dive the gas. I was simply responding to the poster saying he couldn't see any problems with it, and I wanted to highlight one singular potential issue. The thing with normalization of deviance is that it sneaks up on you in small, often pretty reasonable steps, but if the bar keeps moving you end up far from where you started. This might be a small such step, or it might very well be a completely isolated and reasonable judgment call.

 

[ReefHound]

I'm not saying this is a massive breach, or even that I advise OP not to dive the gas. I was simply responding to the poster saying he couldn't see any problems with it, and I wanted to highlight one singular potential issue. The thing with normalization of deviance is that it sneaks up on you in small, often pretty reasonable steps, but if the bar keeps moving you end up far from where you started. This might be a small such step, or it might very well be a completely isolated and reasonable judgment call.

Don't ever drive 1mph over the speed limit, you might normalize it and next thing you know you are driving 100mph through a school zone just as school is letting out for the day.

 

[steinbil]

Don't ever drive 1mph over the speed limit, you might normalize it and next thing you know you are driving 100mph through a school zone just as school is letting out for the day.

Yes, it's easy to ridicule, especially with exaggerated examples. But the more we break rules or guidelines, the less respect we have for them, so it's also important that the rules make sense and are reasonable. It's funny you mention traffic, because I see a lot of unsafe driving from normalization of deviance, but because it's hard for humans to assess risk objectively it keeps happening.

PS
I also find it interesting that some of you are so defensive about this that you feel the need to ridicule, especially when I didn't even advocate not diving the gas. Simply bringing up a potential issue that I think it is worth considering is enough to get people riled up, it seems.

 

[CT-Rich]

Yes, it's easy to ridicule, especially with exaggerated examples. But the more we break rules or guidelines, the less respect we have for them, so it's also important that the rules make sense and are reasonable. It's funny you mention traffic, because I see a lot of unsafe driving from normalization of deviance, but because it's hard for humans to assess risk objectively it keeps happening.

PS
I also find it interesting that some of you are so defensive about this that you feel the need to ridicule, especially when I didn't even advocate not diving the gas. Simply bringing up a potential issue that I think it is worth considering is enough to get people riled up, it seems.

What is proposed is not at all dangerous as a one off event. Normalization of deviance is not a single event, but a process. That occurs over time. How strictly one adheres to standards depends a lot on your personality, your experience those that surround you.

The discussion isn't about whether it is safe, but whether it is off standards. In that sense my soup analogy is a poor one, because the soup, if left out long enough would be unsafe, If it were in a restaurant setting there would be standards set about how long the soup could be stored without refrigeration and still be considered safe.

Diving these tanks adds no addition risk to the dive profile. The OP did not know the answer to his question. He asked, received multiple clear answers, most of which left the final decision to the OP. I wouldn't consider this a first cigarette moment.

The Soviet space program had an enormous number of protocols and rules. Because there were so many, none were followed. That is why, when Mir Space Station had a fire, the fire extinguishers were all still bolted to the walls in launch configuration. NASA had far fewer rules, but they were very strictly adhered to.

IMHO, The OP would do better to find a few standards about what are acceptable dive practices and stick to them rather than try to follow every rule they ever saw in print. What is an acceptable turn pressure, what to do in the event of buddy seperation. What is considered essential gear versus optional gear. What are acceptable dive conditions, depth restrictions. Those are all things that have a direct affect on his safety and can easily be defined by hard restrictions.

 

[BlueTrin]

Yes, it's easy to ridicule, especially with exaggerated examples. But the more we break rules or guidelines, the less respect we have for them, so it's also important that the rules make sense and are reasonable. It's funny you mention traffic, because I see a lot of unsafe driving from normalization of deviance, but because it's hard for humans to assess risk objectively it keeps happening.

PS
I also find it interesting that some of you are so defensive about this that you feel the need to ridicule, especially when I didn't even advocate not diving the gas. Simply bringing up a potential issue that I think it is worth considering is enough to get people riled up, it seems.

Well OP seems very reasonable and open to suggestions. So I suspect, he’s the kind of person to question himself.

I guess, like you said, that, even if he analysed the tank, he is technically not Nitrox certified and unless he took advice from a physical person with valid credentials and who can be trusted, then it’s a bit of a “trust-me” behaviour, since he’s unlikely to find a source of truth he can independently certify to be correct.

 

[EFX]

We all need to trust someone at least to some degree. In regards to analyzing the O2 in the tank he can read the %O2 himself rather than taking someone's word for it. Also, to substantiate that the person has properly analyzed the tank he can ask someone else at the shop to analyze it. If both readings are within a few tenths he can assume the first person followed the correct procedure.

Ultimately, he can buy his own O2 analyzer and analyze the tanks. This was suggested to me by my shop. Their pitch was that even when they try hard to follow all the correct procedures to maintain the analyzers including replacing the O2 sensors every year and calibrate them as needed, they can make mistakes. So, they concluded it would be better to own your own analyzer and analyze the tanks yourself. I was considering it (since I dive primarily nitrox) until they said "Oh, it's only $350 to purchase one." The employee looked somewhat deflated when I said no, so I said "Well, in the end I would just be substituting your mistakes for mine."

 

[KenE]

I wanted to follow up and mention that I did get the tanks analyzed. They show exactly what the % is on the sticker. So now I can state that I saw it with my own eyes. There fine. Next question. Once these tanks are empty. Or low. Can they be filled with air?

I congratulate you on getting them analyzed. After reading the first couple pages I was thinking that one benefit of the certification is the tanks can remain Nitrox tanks. If you go back to "dirty" air (not Nitrox or clean air) then the stickers need removed. Then after coming to your senses and you get Nitrox certified, then you get to pay for getting the tanks O2 cleaned and new stickers. So, why not save the $ and get certified now and use the tanks as they are now. Just my 2 cents.

 

[L13]

We all need to trust someone at least to some degree.

Exactly, you are trusting the design and calibration of the analyzer, you are trusting your instruction on how to use it, etc.

If you didn't design the analyzer yourself, how do you know that it really does what it claims? /s