Recreational dive poll - Nitrox

[TMHeimer]

I rarely dive nitrox and have not been in the presence of anyone else analyzing or watching crew or shop personnel analyze. There are probably others in my position. Personally, I watch.
A 3rd choice in the poll could be you let the crew do it and watch, as Jayf suggests.

 

[Doc]

I see everybody analyze their own gas, maybe because they think I'm undercover PADI Popo. This likely is because I'm a selective grammar nahtzee, but only in reference to using the proper lower case for nitrox. It's such a pre-occupation for me that I lie awake at night wondering if it should be lower case even if the beginning of a sentence.

90% of my diving is on plain old AIR, so I have lots of time to observe the nitrox gotta have it crowd, bless their hearts.

 

[drl]

Almost every LOB I’ve been on requires every diver using nitrox to analyze their gas and enter the mix in their tank and the MOD into a log and sign it. I suppose some could be fudging it but I haven’t seen it.

 

[Gareth J]

A disturbing thread.

Almost a case of Darwin in action.

First rule of using any gas other than air, or potential that could be anything other than air.
CHECK THE GAS - PERSONALLY, do not rely on a third party.


Either standards of tuition have seriously deteriorated or people are not absorbing what they are taught.

The gas should be checked by the diver at the point of sale (dive shop/mixing point).
The gas log should be signed, and the gas mix documented.
The cylinder should be labelled, and the MOD noted.

Ideally the gas should be checked again BEFORE fitting the regulator during assembly of kit.
If there are multiple cylinders of gas in the area, (on the boat), then each cylinder really should be rechecked at the point of fitting the regulator. ESPECIALLY if there are different mixtures on the boat (32%, 36%, air or decompression or custom mixes).
If not, at worst you get an O2 hit, at best you get bent.

I am sure when I did my DM many moons ago, this was very heavily emphasised - and that was for the non-Nitrox qualified DM (, when Nitrox was still considered a technical gas).

More than 20 years of using Nitrox, we ALWAYS check the gas - it is mostly bailout cylinders for me these days as I predominantly use CCR. But we normally have mixed boats of CCR and OC, and the cylinders are personal cylinders, not hired. We still check the cylinder mixes and double check the labelling and MOD's.
There are normally 3 or 4 analysers on the boat.

Scary thread

 

[scubadada]

I either analyze my own cylinders or watch them analyzed in front of me.

 

[tursiops]

As others have said, it is very much dependent on the dive operation, but most commonly (and most recently, in Indonesia) there were two choices for the divers, none of whom had their own analyzers except for me. (1) use the boat's analyzer, do it themselves, and log it themselves. (2) watch the crew do the analysis and fill out the form, then just sign it. I witnessed no one skipping the analysis or just trusting the crew. This may be partly because the group on the boat were all part of a dive club with high standards.

 

[Hotpocket]

Typically the Nitrox analyzing on a dive charter is done at the dock, in the rather short period of time between boarding and leaving the dock. During that time I am busy checking and assembling my own kit, so as to be sure everything is there and working properly before we no longer have the dive shop at our disposal. The last thing I'd be doing is watching other divers analyze their tanks.

 

[BRT]

The option I see is not listed. The divers set their computers based on what the stickers say.

 

[Hotpocket]

The option I see is not listed. The divers set their computers based on what the stickers say.

That would be "Option 2".

You're welcome.

 

[Gareth J]

Just an addendum to my earlier post.

The MOD is the item that needs to be in LARGER numbers on the cylinder. i.e. the most important label. it should allow any one in the water to confirm the safe operating depth of the cylinder (gas).
The % is only required for decompression calculation/planning/setting of computer.

The item that is referred to in the water is the MOD, and should be clear to all.

(Traditionally, the MOD is in the centre of the cylinder. We normally have the MOD on both sides of the cylinder. The % is either below the MOD in smaller lettering, or on the cylinder neck. ) The labelled cylinder allows the diver to double check what should be in the cylinder, with the final analyser check. The Mix and MOD are also noted on the dive log - if the diver is evacuated, the dive details, breathing mix, and dive history go with the diver to the chamber/hospital.

Gareth

PS - although I like the GUE labelling, i.e pre-labelled cylinders with a standard format. We historically have used a lot of custom mixes, so this has never really been a viable option for us. Even now, on CCR my bailout can either be 27%, a Trimix and a deco mix, 50% or 80%.