CO2 retention question

[drperi1]

Uh, DIR teaches all of that, but as theory as I recall. Can anyone post any references to any of the things posted above? Nobody knows what causes narcosis, nobody is sure how O2 is equated into the mixture, and IF the theory is correct, then CO2 is highly narcotic.

BTW, I believe that 30/30 is the recommended mix for the 80 - 120 range ...

Mark[/QUOT RE: "Nobody knows what causes narcosis" is slightly off. Read Bove & Davis, plus assorted other diving med texts. Narcosis is apparently caused by the lipid uptake (physicists and M.D.'s: bear with me) of a gas which "swells" the lipid tissue in the neurotransmitter. The "swollen" nature of the neurotransmitter interfers with the electrical transimission from neuron to neuron.

All gasses have measurable narcotic properties, many of which show at depth; othes at 1 ATM. Think chloral hydradate and nitrous, the latter of which dentists use to calm patients.

The increase or decrease in the amount of gas absorbed by the neuron establishes its' narcotic point of effect. N2 has a value of 1.00 ( based on the alogorithim, the higher the number. the less chance of interfering, so to speak, with neuronal transmission). Argon has the greates narcotic effect at .43.

Of course, as this is science; therefore, all is theoretical.

P.S: The standardized mix/depth restrictions remind me of the (very useful, but only to a point) KISS mentality. Although I accept various DIR principles, not diving "best mix" is not one of them (I also take issue with long hoses used in all situations, but that's another story).

DIR, as a concept, has been around longer than Jarrod has been out of diapers. Therefore, there is more than one interpretation of DIR.

Decide what is best for you: Memorizing one congiguration/set of techniques or incorprating additional knowledge into your personal diving schema.

Dr. Peri M. Blum

"There are old divers and bold divers, but no old, old divers."

 

[PaulChristenson]

If your headache was from CO2 retention...you would have had some of the following signs and symptoms that would have been observed:
hyperventilation,
shortness of breath and tachycardia (rapid heart beat),
headache and excessive sweating,
mental impairment
and finally , unconsciousness.

A more intreresting discussion dealing with CO2 activity related to diving, checkout the following link:
http://scuba-doc.com/CO2acclim.html

Paul in VT

 

[dilligaf368]

To answer the Origional Question....I dive Air! I have been diving for over 32yrs from the surface to (Personal cuttoff of 150') on air. I was a Navy Ist Class diver (He02) and still use Air for all of my diving. I dive air at work....average 850hrs to 990hrs a year up to 70' of water. Also in cold water of the Puget Sound and Alaska.
All these gasses are great and I have dove these gasses, but, for rec. Diving I stick with regular Air. Yes, People can still dive air!!!!! Bill

 

[mer]

To answer the Origional Question....I dive Air! I have been diving for over 32yrs from the surface to (Personal cuttoff of 150') on air. I was a Navy Ist Class diver (He02) and still use Air for all of my diving. I dive air at work....average 850hrs to 990hrs a year up to 70' of water. Also in cold water of the Puget Sound and Alaska.
All these gasses are great and I have dove these gasses, but, for rec. Diving I stick with regular Air. Yes, People can still dive air!!!!! Bill

Bill. This is the DIR forum. We do not dive air for the reasons already stated above, earlier in this thread. This does not mean that people do not or cannot dive air, but they can't if they believe in this philosophy.

 

[HarryH97]

P.S: The standardized mix/depth restrictions remind me of the (very useful, but only to a point) KISS mentality. Although I accept various DIR principles, not diving "best mix" is not one of them (I also take issue with long hoses used in all situations, but that's another story).

DIR, as a concept, has been around longer than Jarrod has been out of diapers. Therefore, there is more than one interpretation of DIR.

Decide what is best for you: Memorizing one congiguration/set of techniques or incorprating additional knowledge into your personal diving schema.

Dr. Peri M. Blum

"There are old divers and bold divers, but no old, old divers."

Dr. Blum,
Some thoughts...
1. GUE trained divers don't use "best mix" for a number of reasons: doesn't give you depth flexibility but more importantly, most of our calculations for technical diving can be rapidly done with our head from CNS to OTU's to shaping our deco. Custom mixes doesn't give you the same reoccuring flexibility, simplicity, scaleability, and rapid rehearsed emergency procedures regarding gas management or the loss of different gases thru the entire dive (including accelerated deco). With practice, the same process is used in the most extreme conditions to the most basic of dives. Let's say you plan for a 150 dive, but are forced to go to 190-200 based on an emergency. Or you lose stages or deco and need to readjust on the fly. Do you say no way, since your gas doesn't support it, and let someone die b/c you're in no position to conduct rescue from gas management perspective? Again, just a thought as to why we do it this way.

You can do reverse engineering and find that the gases we use and the tanks we bring form relationships and are "golden" or "ideal." I won't go into details on the forum,especially the manner in which we do deco, but the same logic applies to BG for recreational dives. That is to say, we TYPICALLY breathe EAN32 verses a custom blend of EAN26,28,36, 38 or 40. The built in safety is the same reoccuring procedures wrapped around a gas that has depth flexibility, MDL and O2 exposure (more appropriate for mix). What you can do with the standard gases in terms of computation from recreational to technical is scarily simple. This allows us to readjust gases, profiles and solve complex problems at depth when they occur. This is in my estimate where GUE education really outperforms & shines in terms of learning the tricks of the trade born from deep exploration diving. Some will disagree how we do it, but I've been clean everytime I do things by "the book" so to speak regarding deco. I don't necessarily do it by the book everytime and when I don't I always feel it.

2. I'm interested in knowing if there is a scenario where the long hose would serve as a hindrance rather than as an enabler.

3. Hogartharian has been around much longer than DIR, but DIR is far more encompassing than hogartharian gear configuration and is fairly recent. It's very easy to mislabel DIR diving without formal education and a solid grasp of how we approach all facets of diving, since we consider these facets all interrelated...

Sincerely,
H2

 

[VTernovski]

BTW, I believe that 30/30 is the recommended mix for the 80 - 120 range ...

GUE recently changed the standard to match PPO level limits of all other standard gases, the new range for 30/30 is 60-100.

 

[cornfed]

GUE recently changed the standard to match PPO level limits of all other standard gases, the new range for 30/30 is 60-100.

Where did you hear about this?

 

[JeffG]

GUE recently changed the standard to match PPO level limits of all other standard gases, the new range for 30/30 is 60-100.

Really? Whats the 100-120 gas then?

 

[Soggy]

GUE recently changed the standard to match PPO level limits of all other standard gases, the new range for 30/30 is 60-100.

Really? I'm assuming this came from Bob and your Triox class and I believe you, but it seems pretty ludicrous to use helium for a 60 ft dive. What is the new limit for 32%, 90ft (1.2 PPO2)? Do you switch to 21/35 at 100 ft? Makes for some awfully short MDL dives at 120'! My thought has always been that there needs to be an intermediate gas in that range, or that 30/30 should really become 28/30 or something along that lines to allow for a little bit of bottom time for those not deco trained.

Yeah, I know the history of the gasses

 

[lamont]

GUE is not going to get very good compliance out of their recreational divers with depth limits of 90 fsw for EAN32 and 100 fsw for 30/30...