Why do I need a Nitrox certification?

[Rhone Man]

OK, I'll play Devil's advocate (hope the Devil can afford my rates! Hah! Lawyer joke).

I think the OP is right. Generally speaking, Nitrox is safer than air. With one exception - oxygen toxicity risk. But we don't require training on oxygen toxicity risk for air, so why is it mandatory for nitrox? Well, the logical answer is that because your partial pressure of oxygen is higher, then your risk of toxicity is higher. But is the risk that much higher? Theoretically a nitrox cert enables a diver to use any mix up to 40%. But in practice, almost all nitrox is done on standard blends of either 32% or 36%. I can't speak for anyone else, but I can't recall the last time I saw 36% except by custom blend. 32% is very close to synonomous with nitrox in non-technical diving.

So what is the MOD for 32%? 110 feet. If you accept the guideline of 1.4 ATA. If like many foreigners you utilise 1.5 ATA you can go down to 120 feet. Truth be told, you could probably go slightly deeper, as if you are just using one cylinder for recreational diving, unless you have the greatest SAC in the world, you 'aint gonna stay there long, and so your risk of toxing is absolutely tiny. And as we all know, you shouldn't be going deeper than 130 feet on a recreational cert anyhow, so what we need to do is make sure that we "grey out" that 10 foot band of water between 120 and 130 feet.

So let's spitball this. Let's say that during an OW course we teach students that as an alternative to conventional air, you can ask for your cylinder to be filled with "safety air". If they do so, this will give them a larger cushion of safety when using the tables, or they can switch their dive computer to give them a more exact replication of the benefits of safety air. However, they need to remember two things: you cannot go deeper than 120 feet using safety air. And (unless they get further training) they can only get conventional safety air - sometimes called EAN32 in older dive shops. If they want custom mixes of safety air, they need further training.

Yeah, I can live with that.
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[RIteen]

Why not just spend the money and get the training to use it properly? I have no experience diving, but I do have experience in regards to chemistry, and I can tell you, that you do NOT want to just inhale any old gas... particularly when it is going to be pressurized.... $150 isn't all that much...

 

[scjoe]

Gotta agree with Thalassamania’s suggestion that Nitrox should be part of every entry level course. Problem is I think Advance and Rescue should be as well. Unfortunately, that’ll run you about $1,000 around here. Just adding Nitrox ups the price of a basic class by $200 in So Cal.

 

[RonFrank]

The reality is that a certification is required to dive Nitrox. Most will have no issue with that, but those who do can talk to the hand! :cool2:

The certification is designed to keep people safe by educating them about the use of various O2 mixes, which BTW can kill you at depth. So you can die breathing pure O2 at 25', that is worth a class, no? The cert is real and failing to understand how O2 works at depth can result in death. Those are very good reasons to pay for a Nitrox class.

There are folks that will say you shouldn't have to pay X, or take class Y, but that is all pointless. The cert has value and is required so if your one of those idiots who is too thick headed to pay for the class then do not dive Nitrox. It's that simple.

I have been diving a while and have always had to show my Nitrox cert even when the shop knows me. Its a policy that all fill stations should have. The guy doing Nitrox fills without a cert deserves to be fired. I seriously doubt his boss is aware this is happening. He is risking his lively hood and if his insurance finds out things will hit the fan. Being a punk kid is cool until the business get closed down because your too thick headed to follow the rules.

 

[DiveNav]

OK, I'll play Devil's advocate ........

..... you cannot go deeper than 120 feet using safety air. And (unless they get further training) they can only get conventional safety air - sometimes called EAN32 in older dive shops. If they want custom mixes of safety air, they need further training.

Yeah, I can live with that.
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I agreee ... with one caveat ....

"And (unless they get further training) they can only do one dive per day".
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In this way we take care of the CNS clock and the daily limits....

Alberto (aka eDiver)

 

[TSandM]

I'm a little rummy after three straight night shifts, but is there anything here that says that the OP hasn't read somebody's Nitrox manual? As Thal says, Nitrox is pure book-learning, except for how to use an analyzer. I don't think there IS any reason for someone to get the cert, if they have read the manual, unless they need it for fills or charters. I think it's a good idea to know a little more about what Nitrox is, what it does, and what the risks are, than just what your computer tells you, but if someone has done their homework, I don't think there is a great deal that an instructor is going to add to a Nitrox class, unless they bring in topics which are not customarily part of the class (as my husband does with his).

 

[chrpai]

The op wrote "I never studied it closely."

 

[JamesK]

So, where does it all end? Sure, you can read about it online and learn everything. Hell, I encourage that. Learn all you can. I will also say that this should be taught in basic OW classes as 32% is now considered a normal breathing gas and is available damn near everywhere.

However, since you can learn Advanced Nitrox and Decompression Theory online and by reading a book, does that make you qualified to go grab some EAN50 and O2 and do some deep deco dives. The same goes with Trimix.



Someone mentioned drysuit courses. Things like this can be learned with a good mentor, but classes are helpful to some. I really don't have a problem with classes vs mentoring in a lot of areas, but when it comes to mixed gases, I tend to draw the line. I am not saying someone is going to die for not taking a class, and that they can not learn everything they need simply by reading. I am saying if I was a shop owner, and someone did not have a nitrox card, I would not fill their tanks.



My main point was that if you did not understand why your computer was telling you what it was telling you, and you do not understand what nitrox is about and waht goes with it, don't dive it. Blindly trusting a dive computer is what I consider unsafe.

 

[boulderjohn]

However, since you can learn Advanced Nitrox and Decompression Theory online and by reading a book, does that make you qualified to go grab some EAN50 and O2 and do some deep deco dives. The same goes with Trimix.

You know well that the challenge of Advanced Nitrox and Decompression Procedures is not so much in the academic part but rather in the skill part. The same is true of Trimix. The real challenge in those classes is all in the skills involved in handling multiple bottles, holding stops, dealing with emergencies at depth, etc. None of that is true with recreational nitrox.

 

[Rogersea]

Flamers need not reply. Where I live the LDS's do not question anyone for c cards or Nitrox fills ever. I have a dive computer and use it. I have been using Nitrox for a couple years now and am just wondering why one would want/ need to get certified for reasons other than getting fills why on vacation and what not. Anything I am missing on this? Why is the certification a supposed requirment. In my experience I have only been asked for Nitrox cert proof when in very touristy areas.
I understand it's cheap to get the cert and all, but what valuable knowledge will a avid OW diver that never plans to do any type of technical diving gain from it?
Thanks in advance.

You gain:

1. Ability to get NITROX fills at reputable dive centers while on Vacation especially remote locations and liveaboards.

2. Knowledge of and how to avoid being stricken with Oxygen Toxcicity.

3. Familiarzation on how to use the log and the analyzer.

I am very surprised that you are getting EAN fills without ever showing a card... That does not happen in my world..

Cheers,
Roger