He unavailable - DeepAir again?

[Germie]

I miss the 'never quit deep air' option.
More seriously, I have seen all the time divers doing dives up to 65m on air. Especially in France you see that quite often.
But now helium is getting more expensive, yes, deep air seems to be returning.
But you also see a growing amount of ccr's. I dive ccr, so going really deep is not a problem with helium then. But if I am on a holiday and I can only get oc dives, then I don't limit my dives to only 40m. My cmas 3* is a single tank air 60m cert. I will never do such deep dives on just a single tank and no decogas, but this means deep air has never been away. I believe cmas also changed from the PO2 1.6 rule to 1.4 a few years ago, and to now 40m. But when I did it, it was for sure a 60m cert (or even the PO2 1.6). No PN2 was mentioned.

 

[DAJ]

The military, federal, NOAA, and a number of others switched over to 1.4 PO2 about eight years ago for the working part of all dives. 1.6 is reserved for decompression stages. That’s probably explains why some folks caution others when they post up using 32% at 130 feet as 1.4 has become the safe margin cutoff for diving and that is what is being emphasized in new nitrox divers.

 

[Nick_Radov]

Deco on air makes for a very long day - I use 80 here because we can't get boosted 100.

Better to use 100% even if you can't get a full fill. You can do a lot of deco at 20 ft with 2000 psi in an Al 40 stage. Or just bring a bigger tank.

Baker's Dozen for not using 80/20 ( George Irvine)

1) This gas was introduced in an effort to overcome the inability of unqualified student "tech" divers to control their buoyancy in open wat...

horizontal-ascent.blogspot.com

 

[Nick_Radov]

You might be surprised about the helium-desert thing. Unless you want I should stop in at Airgas and do my own blending, I'm kinda stuck.

Sure, why not stop in at Airgas? That's what we used to do before the local dive shops started filling trimix. (Actually, I used a welding supply place, but same thing.)

 

[ChuckP]

Better to use 100% even if you can't get a full fill. You can do a lot of deco at 20 ft with 2000 psi in an Al 40 stage. Or just bring a bigger tank.

Baker's Dozen for not using 80/20 ( George Irvine)

1) This gas was introduced in an effort to overcome the inability of unqualified student "tech" divers to control their buoyancy in open wat...

horizontal-ascent.blogspot.com

You might look at the profiles I dive, see what the difference between 80 and 100% are, have you run profiles and seen the differences?

You want to cringe some more???? I trans fill the bottle after every two dives with 36% to get back in the 3000 psi range and I do that 3, 4 or 5 times until the bottle is about 50%.... OMG - can you imagine me using 63%??

You do you, and I'll do me - fair?

My opinion of GUE is wrapped up in that little bakers dozen article that I read years ago. Closed minded group of folks - while they have some great methods and ideas - they come off as arrogant and extremely narrow in their thinking. In my humble opinion, in the general tech diving world, you will be far safer truly understanding what you are taught verses memorizing what you are taught because what you are taught, doesn't apply to all dives.

 

[Germie]

Better to use 100% even if you can't get a full fill. You can do a lot of deco at 20 ft with 2000 psi in an Al 40 stage. Or just bring a bigger tank.

Baker's Dozen for not using 80/20 ( George Irvine)

1) This gas was introduced in an effort to overcome the inability of unqualified student "tech" divers to control their buoyancy in open wat...

horizontal-ascent.blogspot.com

Explain me why 100% is better than 80%. Have you ever calculated the difference in deco time between ean80 and 100%? So I am curious why you prefer 100%.
I already have my ideas, but I hear quite a lot of myths about ean80, so am curious. If it is only that old article, I want to hear extra arguments.

And I don't like doing deco on backgas. So taking just air to go 'deep' (even at 30m you can get easy into deco on air), and do deco on backgas, that is poormans diving and is in most cases not needed happely.

 

[BlueTrin]

Interesting. I renewed my Dan europe yesterday and missed that. Got silver for a number of reasons, one being deeper than 40m (Just in case).

3.95 ATA = 40m on air.

Reading through terms and conditions. General Definitions 31. I assume this is what you are quoting? Not 26 for recreational diver?

My qualification covers 50m on air with non accelerated decompression.

Looks like no just in case allowed for holiday diving.

Yes I was looking at 31.

I have asked DAN Europe if they consider technical diving or recreational if a BSAC dive leader dives under 40m on air within his qualification.

 

[admikar]

Btw I just noticed that Dan Europe has a limit on insurance at 3.95 ATA Nitrogen. So if you dive deep air without telling them, you’ll be breaching the insurance terms.

It seems they are contradicting themselves.
Any ambiguity will work in your favor.
Edited to add: by their definition, that limit applies only to technical diving, which by their definition is Trimix/Heliox gasses. Normal compressed air is within Recreational diving and does not stipulate lower PPN.

 

[Eric802]

Better to use 100% even if you can't get a full fill. You can do a lot of deco at 20 ft with 2000 psi in an Al 40 stage. Or just bring a bigger tank.

Baker's Dozen for not using 80/20 ( George Irvine)

1) This gas was introduced in an effort to overcome the inability of unqualified student "tech" divers to control their buoyancy in open wat...

horizontal-ascent.blogspot.com

I dont think I’ve ever read something that dripped arrogance and condescension quite like that.

 

[MrVegas]

What do you suppose NASA spends on helium to fill a 40 million cubic foot balloon?

"When fully inflated, a football stadium could fit inside the balloon. Technicians inflate the balloons using helium gas."

Types of Balloons

NASA.gov brings you the latest images, videos and news from America's space agency. Get the latest updates on NASA missions, watch NASA TV live, and learn about our quest to reveal the unknown and benefit all humankind.

www.nasa.gov

That would be something like a $160 million fill for divers.