DIR- Generic Marked stages filled with lower O2?

[NothingClever]

This rec3 **** is ridiculous.

I can’t even.

Yeah, strange. Seems inconsistent.

 

[iliketopetsharks]

This rec3 **** is ridiculous.

I can’t even.

I mean, i don't disagree, but could you elaborate a bit further?

 

[iliketopetsharks]

I'm also pretty sure that labeling a 32% cylinder with 21 m MOD is not only stupid, but also a clear deviation from standards.

 

[crofrog]

This rec3 **** is ridiculous.

I can’t even.

It's ok it's master diver now...

 

[MarkA]

I'm also pretty sure that labeling a 32% cylinder with 21 m MOD is not only stupid, but also a clear deviation from standards.

What was this 32% cylinder for in a 40m limited decompression course?

 

[iliketopetsharks]

What was this 32% cylinder for in a 40m limited decompression course?

21/35 backgas with up to 15 min deco on 32%. I think it's a nice stepping stone to Tec 1

 

[crofrog]

21/35 backgas with up to 15 min deco on 32%. I think it's a nice stepping stone to Tec 1

so what like effectively 20 minutes at 130ft?

 

[iliketopetsharks]

so what like effectively 20 minutes at 130ft?

Yes, but with an END of 23 meters. I've done some 40 meter dives on air, and it's hard to describe how much of a difference it makes.

 

[sea_otter]

I have nothing useful to offer, but I will say that the bottle shown on my Rec 3 card has a 70 MOD sticker.

For what it's worth, all stages used in the class were appropriately marked with 100 MOD for 32%.

 

[OTF]

Leaving practice aside for a minute - what is supposed to happen during a real i.e. mandatory gas switch.

Lets say for instance that a diver has taken along a stage marked 21 (or 70) with Nitrox 32 rather than 50 or a stage marked 6 (or 20) containing Nitrox 32 or air rather than oxygen.

Where should the switch occur - at 30 m to the "50" stage since after all the stage contains Nx 32 rather than Nx 50 ? Sounds dubious.

What is the diver's buddy supposed to verify during gas switch - depth vs. mod sticker or depth vs. the hard to read analysis sticker? Which of these reflects the "true" content of the stage if they disagree? Sounds dubious.

And back to practice for a minute - should the divers be practicing switching at the wrong depth or to the wrong gas or having analysis stickers override mod stickers?

While this practice may be harmless on a min deco NDL dive in my view at least this encourages bad habits.

This sounds like a bad, confusing, dangerous situation that should never occur underwater, and if it ever did, should result in a frank post-dive discussion on how the team got there and how to ensure it never happens again. It's not that hard to properly mark cylinders! Which includes covering or removing inaccurate numbers so nobody needs to doubt, disobey, or think around them. To add to your scenario, what if there were also a stressful (but manageable) emergency compounding the situation? Confusing deviations such as this can make tragedies out of mildly bad situations.

I'm not really a "DIR Diver", I deviate from "Right" on plenty of things for plenty of reasons; some good, some bad, and some plain lazy. But clearly marking mixed gas tanks for technical dives is so easy and so important that I fail to see how this is a 5 page discussion.