Can Narcosis be managed?

[divingabe]

This is a cave diving forum, let's ask "can narcosis be managed in a cave environment".

In the context of cave diving, back in 1996 I was the accident analysis committee chair for the NACD and someone asked about the number of deep air cave diving fatalities. The records that I had indicated that between the 1960s and 1994, approximately 55 people that had some level of cave training died while deep air diving. This happened to align with what I was taught by my cave instructor, deep diving was the #1 cause of fatalities of trained cave divers.

Of those, 2/3rd of them died on dives at depths between 150-180'. This result surprised me, I was personally expecting most of the fatalities to have been at much deeper deaths (over 200'), 150' on air didn't seem that extreme of a depth to me at the time.

Best I could figure at the time is that the likely chain of events for many of these, which I still believe as the most likely scenario today, was:

1. Primary light dies - remember the period we're talking about was when halogen bulbs and wet cell nicads were common, primary lights were not nearly as reliable as they are today
2. In the process of deploying a backup light, something happened (silt out, turned around, or off the line)
3. Stress caused increased gas consumption
4. Between being at 6ATA and increased gas consumption from stress as well as the delayed reaction time from slight narcosis impairment, there was a reduced amount of time for problem solving - diver runs out of air at some point near the exit.

Life has risks, driving along US27 to Peacock Springs on a foggy morning can be one of the most hair raising experiences a person can ever have. Some risks can be managed, some can't. When figuring out a personal risk / reward tolerance for deep air cave diving, I would hope the person contemplating it would also consider the impact to the community in the event something goes wrong. In the last five years we've lost access to several amazing sites, I'd hate to be the one to cause other places to get shut down simply because I didn't want to buy some helium.

Thanks Ken for the supportive post to my personal opinion. When diving whether in caves or open water personal safety should not be compromised for lack of CASH. Any accident also involve others whom had no input on your decision a clear head is a necessary portion of the diving experience, well for all except maybe James!
Gabe

[SUB ZERO]

I'm pretty firmly entrenched in the "use helium" camp myself even though I have done my fair share of stupid stuff on deep air dives, but if you didn't want to discuss it in an overhead environment, then why did you post on cave divers forum?

For two reasons that have a strong overlap.

1. The ability to have a mature discussion, specially one sensitive subjects, is limited to this forum and not the other more popular ones.
2. Experience and wisdom is higher on the cave diving forum.

If I was a newly certified open water diver and wanted to know which snorkel to purchase then I would not bother the folks on this forum. If I was heading to the caribbean and wanted to know if I should go to Bonaire and Belize then I would not bother the folks on this forum. For a discussion on deep air and narcosis ....

Hope you get the idea. Special thanks to all who replied.

[rddvet]

Is this thread born from the scubaboard thread where the dude believes he doesnt get narced cause he doesnt feel it?


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[bent]

I think the statistics pretty clearly back up that even at "shallow" depths, the narcosis of diving air at 150' in a cave can reduce problem solving abilities to the point that someone couldn't overcome a problem in time, and I suspect if you look at 120' you'd probably see the same. A firm 100' END in a cave makes a lot of sense, but an overhead environment with significant penetration, navigation, silt, etc is completely different than a wall dive in a warm tropical environment; diving air to 120' or even 130' in the ocean may not be the end of the world.

At least for me 120 is pretty big difference to 150. At 150 I feel narced most of the time. At 120 I have hardly ever felt anything. I agree that penetration, navigation, silt, etc is not gonna help but since most cave dives are done in Ginnie/Ressel/JB type caves I don't think it's a major factor. Who's really going to get Trimix for 105 feet OC dives? Are people actually doing that?

Outside of destinations it can be pretty difficult to get He. So it's either air (within reason) or don't dive. Same with buddy vs solo. If it's either solo or not diving, I'll dive solo.

[SUB ZERO]

Is this thread born from the scubaboard thread where the dude believes he doesnt get narced cause he doesnt feel it?


Sent from my iPhone using Tapatalk

I need to see that one.

[WEPIV]

I'm only speaking for myself here, and I bet my "deep" diving days are over anyway. But being someone who doesn't get high or drink alcohol anymore, I happen to love that warm fuzzy narcosis feeling between 140 and 200 feet. Not in the overhead environment though. I made a rule for myself years ago not to go below 130 or 140 in a cave or wreck on air.
I used to dive at 40 Fathom Grotto fairly often, sometimes on mix and sometimes on air. I could really tell the difference between the two diving experiences dropping down to the van at around 160 and then taking the line off the back of it to around 200 feet. Also, one time I was diving Indian on trimix and coming out I switched to low nitrox as it got shallower and I immediately felt the difference just with one breath. That was an eye-opening experience.

[scubadude]

I skipped to the end of this thread the minute I clicked on it.
Moral to the story is: I need helium.
I will go ahead and start a new thread on that.
Wow, it is getting complicated....
edit: to get helium....

[bletso]

It all depends on where you are. I can get as much as I want.