DIR- Generic Why use GUE nitrox only

[justinthedeeps]

Maybe the shop didn't even really bank air?

Waste of space if you're banking a lot of 32%, 21/35, helium, oxygen etc.

I wouldn't bother banking air either, if I was planning to do almost exclusively 32% and trimix fills and that is what most customers actually wanted.

Most people diving in cold environments believe that they feel better on 32%, even for max depths of like 15 metres. It's not just GUE ppl

High ppN₂ sucks, and might be turning your body into seltzer water on literally ALL of your dives.

But air is also evidently still usable to like 60 metres for single tank bounce diving or 'extended range.' Just like getting wasted in the bar and driving home. YMMV

 

[crofrog]

Tell me how it is safer as Oxygen is toxic at any level although our bodies have evolved to handle 21%. Nitrogen is not toxic but causes problem when excess is dissolved in the bloodstream which with an NDL in excess of 6 hours is really not an issue in this case.

So should you breath 13% so that your ppO2 is .21 at 21ft…

Your body isn’t evolved to breath compressed gas at depth

 

[grf88]

So should you breath 13% so that your ppO2 is .21 at 21ft…

Your body isn’t evolved to breath compressed gas at depth

You still have not explained how 32% is safer at 21 ft. than air.

 

[NW Dive Dawg]

You still have not explained how 32% is safer at 21 ft. than air.

Maybe I am missing something, but at 21 feet, 02 up to 90% is WAY better than air.

 

[cfberry]

Since GUE adheres to a maximum END (equivalent narcotic depth) of 30m, there's no benefit to using air, and only drawbacks. Here in Norway we pay the same for an air fill and a Nitrox fill, so there isn't even an economic excuse. I understand that is different on the other side of the pond. That said, the GUE divers I know will dive air (to 30m) if that is all that is available.

I think the attitude of some (old school?) GUE divers around using air is probably a response to the mainstream agencies demonizing Nitrox as "voodoo gas" back in the day. It seems a little out of place these days.

I think sparragus hit the nail on the head when it comes to the advantages of standard gases, and GUE also use EAN32 to blend other standard gas mixes, so I'm guessing you will find banked 32% in most GUE-centric dive shops.

thanks

 

[crofrog]

You still have not explained how 32% is safer at 21 ft. than air.

Less dissolved inert gas. Same as always.

 

[justinthedeeps]

You still have not explained how 32% is safer at 21 ft. than air.

Ok fine, it's not. Okay!

But you are breathing a Standard Gas, and doing anything GUE does is safer. Now get back into delta formation!

But ok 6 metres, 1.6 atm.
Say you get totally saturated at that depth on compressed air (not sure how long that takes...10+ hours?)

Is the "surface GF" now like 160%, aka 60/60? Is the math actually that simple?

Surface immediately. Any risk of the bends? I honestly don't know.
Has the experiment been done?

Take a plane flight, cabin pressure is typically ~20% less than where you boarded the plane. Is anybody getting the bends from flying on aircraft? How low does the cabin pressure have to be before there is a risk of the bends from a fast takeoff, or loss of cabin pressure?

https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/dcs.pdf

Do astronauts on space rockets get the bends? I heard a rumor that they pre-breathe oxygen prior to launch to prevent this. That would be like breathing 100% oxygen at 6 metres before you surface. Kind of. (Not really though? lol)

 

[steinbil]

But ok 6 metres, 1.6 atm.
Say you get totally saturated at that depth on compressed air (not sure how long that takes...10+ hours?)

Is the "surface GF" now like 160%, aka 60/60? Is the math actually that simple?

Nope. That's not how Gradient Factors work.

 

[leadduck]

most of "why does GUE ..." can be answered with "because it was designed as a training program for cave diving in teams. Outside of that context, YMMV."

In open water decompression diving we usually accept that divers carry different gases and have different decompression schedules. The air diver has longer stops than the buddy on EAN32 who is already done with deco but freezing and wants to get out. Such inconsistency can be inconvenient and surprising, but is usually not a big problem in open water, and we value freedom.
But when that same team has to exit a narrow cave single file in low viz, each diver having a different decompression schedule that the others don't know is a problem. They better be very aligned and minimize deco in the overhead, else diving solo would be safer.

 

[steinbil]

In open water decompression diving we usually accept that divers carry different gases and have different decompression schedules. The air diver has longer stops than the buddy on EAN32 who is already done with deco but freezing and wants to get out. Such inconsistency can be inconvenient and surprising, but is usually not a big problem in open water, and we value freedom.

I don’t know the royal «we» you’re talking about, but that’s a hard disagree from me. Sacrificing safety and team integrity on possibly the most dangerous part of a dive - the ascent - for some weird notion of personal freedom that comes with no significant advantages of any kind, is mindblowing to me.

Doing tech decompression dives with different gases in the team is either solo diving or just wildly inefficient for no benefit - neither of which appeal to me.

PS.
This might belong to the pub, but this contorted idea of personal freedom makes no sense. Owning a weapon is not freedom. Sending your kids to school without worrying about school shootings is freedom. Diving different gases is not freedom. Having the same gas and deco schedule, and team redundancy and shared resources gives flexibility and freedom to focus on WHAT MATTERS. /rant