Nitrox: Should I be worried?

[gcarter]

This is a "Trust but Verify" situation. And not just with the O2 mix.

* I should be able to trust that the operator provides a tank with 3000 PSI (or whatever full is) but you need to verify that with your pressure gauge before you jump in the water. Short or even empty tanks get delivered all the time.

* If you see the operator diligently measuring and labeling tanks with the O2 mix, then it's likely to good to trust that number. If you see no evidence that anyone has actual awareness of the mixes, then you need to measure it yourself.

If you can't measure I would still Pay for the Nitrox, but set your computer to an Air Mix and just know that you are Probably getting a better safety buffer. Worst case you are out 10 bucks and no damage done.

Disagree with this. Always measure, never trust. Worst case isn't the money, it is exceeding your PPO2and taking a CNS hit for your troubles.

 

[Barnaby'sDad]

I have never gone anywhere where an op supplying me a nitrox tank did not also have an analyzer for use and make you sign off on the mix. Won't say it can't happen, but I have not run into it.

Yup. For the dives that I completed in the scenario that was mentioned ("I just arrive at the marina, jump on the boat, and they setup my gear, attach the tanks, etc.")....the crew brought around an analyzer and log book (you log your tanks and initial) and tested every tank.

 

[Bob DBF]

But you are right, at first look I don't find anywhere that specifically says to check the odor of your air cylinder. That may just be some hand-me-down procedure that tends to get passed along from instructor to instructor, and certainly nothing wrong with it.

Could be more of a hand me down from when getting blow by from a compressor was more prevalent. Compressors now don't seem to have the problems they once had, probably from five decades of improvement. But let's face it, if the air smells, regardless of the reason, it can't be good for you.

Sounds reasonable, but you are right that is first time I have heard that specific concern. You also seem to imply that burning compressor oil is odorless. I'm not going to go burn some to check, but I am a bit skeptical in that regard. Thoughts?

In my experience from thee incidents in the '60's and '70's, I caught two tanks from the taste and smell of oil when checking the reg. The third, however seemed fine but got the taste and smell of oil approaching 60'. I grabbed my buddy and headed up, obviously any CO involved was not enough to impair us in that amount of time. With the improvement in compressors and lubricants, there may not be as big a margin of error between taste and CO imparment.

The last event was in '79 and I haven't had a bad tasting tank since.

And I did not mean to imply that a sniff test is fool proof, just that it is good advice.

Yes!



Bob

 

[Rred]

OK, now you folks are making me paranoid. Or maybe I should say "wary".

If I'm going to rashly assume a rental tank is what it is supposed to be...or maybe, I should be carrying a monoxide and co2 tester to use all the time, not just a nitrox check?

Like the lady at the airline ticket counter used to say "Did you pack your own luggage? Has anyone else handled it?" Where does it end?

 

[AdivingBel]

@Rred The internet...paranoia...conspiracy theories...nah.

 

[Storker]

Where does it end?

It never ends. You just have to find your own balance between risk acceptance and paranoia.

After all, the most risky part of rec diving is the drive to the site. Provided you more or less follow established guidelines.

 

[Joneill]

OK, now you folks are making me paranoid. Or maybe I should say "wary".

If I'm going to rashly assume a rental tank is what it is supposed to be...or maybe, I should be carrying a monoxide and co2 tester to use all the time, not just a nitrox check?

Like the lady at the airline ticket counter used to say "Did you pack your own luggage? Has anyone else handled it?" Where does it end?

It all about what level of risk you, as an individual, are willing to accept and everyone has different standards!

 

[DandyDon]

If I'm going to rashly assume a rental tank is what it is supposed to be...or maybe, I should be carrying a monoxide and co2 tester to use all the time, not just a nitrox check?

The DiveNav - Products - cootwo will protect you on both risks, and much more if you want to get into it. It's a little pricey, but cheaper than a funeral.

It never ends. You just have to find your own balance between risk acceptance and paranoia.

After all, the most risky part of rec diving is the drive to the site. Provided you more or less follow established guidelines.

I do incur a lot of risks from my own doing, but I want a fair chance on services provided to me that could injure or kill. I want the cab driver and the boat captain sober, trained, and licensed at least, and I want the gas I breathe to be non-toxic. Sadly there is little I can do to insure those drivers meet minimum standards nor the fill shack runs clean compressors with clean filters that are not overheated - but I'll do what I can. The only study ever done on tank gases by a lab showed a 3% failure rate. Many of those failures were gross failures, and even tho the lab samples were taken at the owners discretion, the requirement was never enforced, then it was dropped.

I have seen nitrox tanks that were dived by divers thinking they were air, and were rather upset about their recent risks for the depths we'd been to; I've seen suspected CO hits causing most of my group to get ill - everyone who dived air from one source (who became the worst dive op of my experiences as the week went on), but not the nitrox divers who got their tanks delivered by another op (whose compressor I visited at the end of the week, and I was impressed); and I've seen first hand toxic tanks, that I rejected.

 

[LarryR]

On a recent dive in Punta Cana I ask to analyze my tanks. After over hearing a couple of employees question this I was allowed to do so. 3 tanks of 32% registered from 25 to 27%. These dives were shallow and could have been done with air but they had no issue wanting to charge me for Nitrox.

 

[SandyRobinson]

On a recent dive in Punta Cana I ask to analyze my tanks. After over hearing a couple of employees question this I was allowed to do so...

Wow - bothers me that a shop would question whether or not you can analyze your own tank. I analyze all of mine - whether air or nitrox for 'O2 and CO.