Not diving to greater than 30m/100ft unless with helium

[dumpsterDiver]

I don't claim that a "low tolerance for narcosis" to be a weakness. I am just quoting something that someone else posted. If I misinterpreted the nature of that person's post, they are welcome to correct me.

With regards to the person/event that precipitated that person's post, I will say that the diver did not refuse to use helium. She simply obeyed her usual protocol of using 32% on a dive that was not planned to go deeper than 30m/100ft.


What I am getting out of DD's posts is that those who cannot tolerate diving a bit beyond 100ft without helium due to narcosis have a serious weakness/vulnerability that other divers do not have.

It's entirely possible that I am misinterpreting the spirit of those posts.

If a person cannot (well) tolerate diving below 100 ft on nitrox or air due to their personal susceptibility to narcosis AND they chose to dive in a high current environment where the (potential) depth exceeds their "comfort level" - then I think they are putting themselves in a situation where they are "vulnerable" ... I'm not sure what would be the best term to use in this situation.

I am claustrophobic. If I decide to enter into tight restrictions which will reveal and emphasize my "weakness", some people may think that is unwise. I doubt many people will conclude that all the divers who do not enter into tight overhead situations are claustrophobic.

 

[RJP]

What I am getting out of DD's posts is that those who cannot tolerate diving a bit beyond 100ft without helium due to narcosis have a serious weakness/vulnerability that other divers do not have.

I think, for some reason, you're reading "weakness" as an insult... when none is intended. A diver who is highly susceptible to narcosis at recreational depths DOES have a vulnerability that most other divers do not. Full stop. There's no debating that, really. How serious that vulnerability is really depends on the type of dive in question and the way the diver is impacted by the narcosis.

 

[Akimbo]

I think, for some reason, you're reading "weakness" as an insult... when none is intended. A diver who is highly susceptible to narcosis at recreational depths DOES have a vulnerability that most other divers do not. Full stop...

I concur. I have always had lousy cold tolerance and definitely underperformed divers with higher cold tolerance. I was able to manage it — at least until the hot water stopped, I punched a hole in the drysuit, or the dive lasted longer than expected. Tolerance to IGN, compromised vision, difficulty equalizing, not being able to bench-press as much as some other diver, or about a thousand other factors simply generates the profile we must learn to contend with.

Another important factor is it isn’t something you master and forget. It is a moving target as you age, gain experience, physical abilities change, and education join the party.

 

[AfterDark]

Forgive me for reading the post but DD also used the word vulnerabilities however the word weakness was latched onto. Vulnerable is probably the more accurate word to use. We’re all different. I’ve only used air; I’ve been noticeably narced @ 80FSW; other dives I’ve been to >100FSW with no noticeable effects. Given the right set of circumstances any diver can be affected past 50FSW IMO. It isn't weakness it just is.



Many members seem to envision her as a very strong and capable diver. From my perspective, these two issues represent serious weaknesses (or at least vulnerabilities) when functioning in a high current, drift dive situation with no visual references and when drifting in water that she knew would cause her significant narcosis.

 

[kafkaland]

My experience with narcosis is somewhat limited, but I definitely notice a cognitive slowdown in cold water around 120ft, like on a typical Great Lakes wreck dive. I dive sidemount, and notice myself fumbling with unclipping the long hose reg just a tad longer than in the cenotes in Mexico. Or, it just seems to take a second or two longer to remember which way the anchor line is. It's only on cold water, I never noticed anything like this in warm water at comparable depths. I don't know if I'm unusually susceptible to narcosis, or just very aware of my mental and physiological state. Either way, I'm planning on taking AN/DP/Helitrox next year, and I'm looking forward to seeing the difference some helium in the mix makes.

 

[boulderjohn]

I do not have any deep dive experience with Lynne--the deepest we ever did together was about 100 feet. I do know the things she said in support of the GUE limit of 100 feet END. For part of our time as friends I was also associated with UTD and had a similar limit. In all my UTD dives, I was not allowed to go below 100 feet without helium in the mix. She and I talked about it. My impression is that she was not any more affected by narcosis at those 100-130 foot depth than the average diver. My understanding instead is that she ascribed thoroughly to her GUE teaching and thought the degree to which the average diver was incapacitated by narcosis at those depths was too much. Thus, the degree to which she was incapacitated had to be too much, even though it was no more than what most other divers experience. I don't feel comfortable putting those words in her mouth, though, and devoutly wish it were not necessary. I don't see any reason to speculate on some sort of narcotic episode--it is unfounded and uncalled for.

 

[John C. Ratliff]

I 'm with BoulderJohn on this, as this speculation about narcosis being a factor in this accident is not correct. Here are a couple of reasons:

--she was well into her ascent when she disappeared. Nitrogen narcosis evaporates upon ascent; it's gone!

--you have mixed up symptoms of narcosis with problems of sometimes experiencing vertigo; they are not the same, and do not have the same causes. If Lynne were still around, she would be giving us detailed information on the two, along with similarly detailed information on potential causes of vertigo (temp differences on the ear, broken eardrum, pressure/equalization problems, etc.).

So speculate all you want about the appropriateness is using helium, depths at which it is appropriate, etc., but leave TS&M out of it!

SeaRat

PS--dumpsterDiver, if you have problems with claustrophobia, why do you dive in dumpsters? Inquisitive minds would like to know (mine, actually). I once dove in a dump pond looking for a duck hunter's shotgun (in my college days--got $5, but no shotgun). Zero visibility, dirty, infected water too; I went to my apartment, took an hour-long shower, scrubbing myself and my wet suit with Visohex, and had no after effects. My dive buddy got some boils when he did not take precautions after the dive. [This is a joke, meant to distract from this thread's subject and lighten the dialog.]

 

[BRT]

I've never breathed a breath of helium but I'm convinced that I don't think, remember and react as well at 50 feet as I do at 30 and it doesn't get better as I go down. That said I've been functional as deep as I have gone, except when I've felt the affects of CO2. Makes my head buzz, makes me feel afraid and I don't have to be real deep for it to have that affect. Scares me worse than depth and I have a healthy respect for nitrogen narcosis. Makes me wonder if CO2 isn't worse than nitrogen?

 

[tomfcrist]

In DD's original post quoted by the OP, I think he was trying to signify that with her known issues experiencing mid water/no reference vertigo, ANY amount of narcosis becomes a serious liability. I don't think he was referring to her as a weak diver...but as a diver whose vulnerabilities could easily be magnified by narcosis. That being said, the vertigo issue all by itself could be a massive problem under the right(or wrong) circumstances.

 

[Lorenzoid]

I've never breathed a breath of helium but I'm convinced that I don't think, remember and react as well at 50 feet as I do at 30 and it doesn't get better as I go down. That said I've been functional as deep as I have gone, except when I've felt the affects of CO2. Makes my head buzz, makes me feel afraid and I don't have to be real deep for it to have that affect. Scares me worse than depth and I have a healthy respect for nitrogen narcosis. Makes me wonder if CO2 isn't worse than nitrogen?

CO2 is indeed believed "worse than nitrogen." The problem is that one can only control their breathing so much. We can practice, but most of us will never be yoga masters or commercial divers.

Good article here on CO2 and narcosis: https://www.globalunderwaterexplorers.org/carbon-dioxide-narcosis-and-diving