PSAI Narcosis Management course - 73m on air

[boulderjohn]

breathing gases all combined is 3% of the total use of helium. biggest use is in cryogenics in industry, medicine and science. the LHC at CERN uses 96 metric tons of helium to cool it. then its obviously used for welding, and for inert atmospheres for science and industry.

and, yes, once helium gets too expensive there will be a lot of people in important positions in the economy whose businesses will start to get hurt by it.

i

Don't forget the Macy's Thanksgiving parade and the blimp hovering over the golf tournaments.

 

[wedivebc]

It might be time to rethink our attitudes toward deep air. I was just told by Praxair who I have been buying helium from for 10 years that they don't expect to have any more available until fall. Another supplier said they had some but it was $200 a T. No thanks.

 

[syntaxerrorsix]

It might be time to rethink our attitudes toward deep air. I was just told by Praxair who I have been buying helium from for 10 years that they don't expect to have any more available until fall. Another supplier said they had some but it was $200 a T. No thanks.

Oh that's just dangerous, surely you will die. Best to quit now.

 

[Kevrumbo]

I recently took this course at Capt'n Gregg's in the Philippines with my instructor & friend Mark Cox, ad thought I'd share my experiences and thoughts with you.

Firstly, I don't want this to turn into a deep ar-bashing thread. This is a deep air course, if deep air isn't for you then obviously you wouldn't do it. However if anyone has any questions or constructive criticisms I'll try to address them.

I should also say that I make this post as a student of the course - I have no affiliation with or debt to PSAI.

The course, which was conceived by Hal Watts, deep air record diver, was originally taught at 40 Fathom (73m) Grotto in Florida. It's only taught by a limited number of highly qualified/trained instructors - I understand Capt'n Gregg's is the first IDC outside of the USA.

The course is NOT about encouraging people to dive deep air, and does not 'certify' people to dive to the depths involved; rather the focus is on teaching skills to allow you to safely plan deep dives & manage the narcotic effects - whether using air, trimix or whatever.

There are 6 levels to the course (although you need explicit permission from PSAI headquarters to progress to level 6), which cover dives to 30, 40, 46, 55, 61 and 73 metres. In order to progress to the next level, you must complete the previous level whilst demonstrating proficiency and completing the skills and checks required, before being given the okay to progress to the next level. Multiple dives to each depth can be and usually are required.

My previous training includes Advanced Nitrox & Decompression Preocedures (TDI) and Rescue (PADI).

All course dives are done using a descent/ascent line, with a safety bottle (100% oxygen) suspended at 6m, accompanied by your instructor at all times, and - in the case of the level 4-6 dives (55, 61 and 73m), a second PSAI instructor (and in my case, a support diver at 12m).

Back gas was always air, in doubles, with either 1 or 2 stages of 50% and 100% respectively, depending on target depth.

The 'core' of the course is a PSAI slate on which certain information is recorded before and during the dive, such as:

- Starting tank pressure
- Target depth
- Descent pressure
- Level off depth
- First stop depth
- Depth at 4 minutes dive time
- Pressure at 6 minutes (self and buddy)
- Pressure check at every subsequent 2 minutes of bottom time
- Turn pressure (minimum)
- Object identification and compass heading
- 1 minute to ascent time signal
- Ascent pressure
- First stop pressure

etc etc - the idea being to give you a set of tasks to maintain your awareness and monitor depth, time and tank pressure

Anyway, enough about the details and on to what I thought...

It was great! Having done deco dives previously to 45-65m, I felt much more in control and aware of my situation. Certainly I was narc'd, but able to cope with the requirements of a technical dive much more easily using the skills I learned.

I'd definitely encourage anyone who is interested in deep diving to try this course(you can do as many or as few levels as you are comfortable with). I feel like a much better and safer diver as a result.

Resurrecting this OP after my own Deep Air/Dark Narc encounter to 80m on Oil Rig Eureka here in offshore SoCal two months ago, in 12deg C water temp depth at the time. All it took was three frog kicks into the current at depth, and the over exertion/over-breathing the regulator, high density & flow viscosity of breathing Air mix & resulting CO2 Retention of the Dark Narc Vicious Cycle hit me immediately. In the dim ambient light, the only thing I was able to cognitively perceive was my Petrel Dive Computer flashing an extreme PPO2 Warning prompt of 1.9, and it took a few minutes focused concentration just to hang onto a support beam and try to regain a nominal breathing rate before starting the ascent. Not at all pleasant and I don't want to do that again. . .

Tortuga68 mentioned in another later thread that the highest PPO2 Deep Air he's been exposed to was 2.34. This implies an incredible Depth of 11ATA , or just over 100m. No judgment, or admonishment intended, but some objective FYI reference data & notes should you -or anyone else- feel compelled to do these Deep Air Dives:

PPO2 Exeptional Exposure Table
We removed the Exceptional Exposure Oxygen tables from the NOAA diving manual 4th editon because there was fear that if the general public saw them printed that they might take it as an endorsement to use them.

The NOAA exceptional exposure limits are set for extreme emergencies only and are not for routine use. IE: should be used for life saving only.

These are for a working dive meaning with lite exertion. Remember that there are a variety of factors that come into oxygen toxicity, and crossing the 1.6 atm 45min line does not guarantee convulsion, it also does not guarantee it won't.

NOAA OXYGEN
EXCEPTIONAL EXPOSURE LIMITS
PO2 Minutes

2.8 5
2.4 10
2.0 30
1.9 45
1.8 60
1.7 75
1.6 120
1.5 150
1.4 160
1.3 240

As you can see the exceptional times allow you a fairly large margin to use this method for an "escape." The table is NOT linear. Note that exceptional exposures are DANGEROUS and can only be done once in a day. . .

Joel Silverstein

Deep Air OxTox vs Inert Gas N2 Narcosis
1. I am the guy that set the world depth record on air with scuba in February 1990. That was to 452 feet and I broke it again in 1993 when I went to 475 feet. This is not diving for anyone but highly experienced trained professionals of that era. (In those days, helium was not widely available in remote areas so you either worked on air... or didn't do the dive. Today helium is widely available and the preferred equipment would be a closed circuit rebreather, not open circuit scuba.) Yes, the PO2 is high. But you have to have a fundamental understanding of oxygen physiology to grasp that it is "dose" not partial pressure alone that defines the risk. Brief exposures to high PO2 can be accommodated by some individuals. It just means that your time at that exposure will be severely limited. A far bigger problem for some is the issue of inert gas narcosis. More people have been overcome by this than oxygen toxicity. In fact, to my knowledge, there are only six persons alive today that have ever been deeper than 400 feet on air and survived: Jim Lockwood, Tom Mount, Jim Bowden, Joe Odom, Dan Manion and myself. Also, nothing in diving is "safe". Safe literally means "without risk". What we did was calculated risk within our own ranges of comfort and we had no issues. But none of us would call it "safe" and we stridently urge others not to attempt similar dives. Most people belong above 200 feet and should stay there. . .

Bret Gilliam
OCEAN TECH
54 Stonetree Rd.
Arrowsic, ME 04530

 

[dumpsterDiver]

Resurrecting this OP after my own Deep Air/Dark Narc encounter to 80m on Oil Rig Eureka here in offshore SoCal two months ago, in 12deg C water temp depth at the time. All it took was three frog kicks into the current at depth, and the over exertion/over-breathing the regulator, high density & flow viscosity of breathing Air mix & resulting CO2 Retention of the Dark Narc Vicious Cycle hit me immediately. In the dim ambient light, the only thing I was able to cognitively perceive was my Petrel Dive Computer flashing an extreme PPO2 Warning prompt of 1.9, and it took a few minutes focused concentration just to hang onto a support beam and try to regain a nominal breathing rate before starting the ascent. Not at all pleasant and I don't want to do that again. . .

Tortuga68 mentioned in another later thread that the highest PPO2 Deep Air he's been exposed to was 2.34. This implies an incredible Depth of 11ATA , or just over 100m. No judgment, or admonishment intended, but some objective FYI reference data & notes should you -or anyone else- feel compelled to do these Deep Air Dives:

240 is kinda deep on air, but why in the world would you over-exert yourself and then fail to initiate an ascent? You hang out at the deepest portion (I assume) of the dive trying to re-gain your exposure. I would have been pressing the "up" button, and concentrating on full exhalations, until I hit 180 or something.

 

[Dr. Lecter]

240 is kinda deep on air, but why in the world would you over-exert yourself and then fail to initiate an ascent? You hang out at the deepest portion (I assume) of the dive trying to re-gain your exposure. I would have been pressing the "up" button, and concentrating on full exhalations, until I hit 180 or something.

I'm also left wondering what someone whose self-described limits and experiences with air in calm, clear, warm water at the shallow range of ~60m weren't all that great...was doing at 80m on air in worse conditions.

 

[dumpsterDiver]

composure.. not exposure

Also, there is a HUGE difference between 60 and 80 meters on air.. For me, 60 m is no big deal,, while 240 ft would be... no way unless I have a damn good reason and there hasn't been one for a long time for me.

 

[PfcAJ]

loony tunes.

 

[Kevrumbo]

240 is kinda deep on air, but why in the world would you over-exert yourself and then fail to initiate an ascent? You hang out at the deepest portion (I assume) of the dive trying to re-gain your exposure. I would have been pressing the "up" button, and concentrating on full exhalations, until I hit 180 or something.

No. You don't want to hit your "up" button in a badly narc'd condition and risk an out of control panicked ascent. (80m is roughly 262')

I'm also left wondering what someone whose self-described limits and experiences with air in calm, clear, warm water at the shallow range of ~60m weren't all that great...was doing at 80m on air in worse conditions.

Oil Rig Eureka off the SoCal Coast in a deep wide open "bottomless to 150m" ocean channel between the mainland & Catalina Island has some of the most variable unpredictable current & viz conditions at depth versus the surface -i.e. You might have calm seas on the surface, but a ripping current at 18m, and a swirling washing machine down beyond 30m, then paradoxically calm ccomditions again all the way to 90m. Diveboat procedure & protocol requires divers to remain inside the oil rig structure in all phases of the dive profile especially upon surfacing: Absolutely no drifting deco because of shipping lane boat traffic, and afternoon marine layer/surface fog conditions which can reduce surface visibility quickly. Despite the challenging conditions, a lot of the deep open circuit and CCR divers in LA do their training dives there at Oil Rig Eureka because of its close proximity to the Port of Los Angeles/Long Beach.

 

[Dr. Lecter]

Oil Rig Eureka off the SoCal Coast in a deep wide open "bottomless to 150m" ocean channel between the mainland & Catalina Island has some of the most variable unpredictable current & viz conditions at depth versus the surface -i.e. You might have calm seas on the surface, but a ripping current at 18m, and a swirling washing machine down beyond 30m, then paradoxically calm ccomditions again all the way to 90m. Diveboat procedure & protocol requires divers to remain inside the oil rig structure in all phases of the dive profile especially upon surfacing: Absolutely no drifting deco because of shipping lane boat traffic, and afternoon marine layer/surface fog conditions which can reduce surface viability quickly. Despite the challenging conditions, a lot of the deep open circuit and CCR divers in LA do their training dives there at Oil Rig Eureka because of its close proximity to the Port of Los Angeles/Long Beach.

That's all well and good. Why were youat 80m, on air, for this dive?