Nitrogen Narcosis - Deep air dives

[tursiops]

These kinds of stories really scare me. The variability between individuals who can and can not function at depth is dramatic.

120 feet is NOT deep from my personal perspective on narcosis, but for that individual - on that day- it certainly was.

The message to new divers is very confusing:

• divers are drunk and they don't know it,
• divers who say they are acclimated (to depth) are foolish and delusional,
• diving past 100 on air or nitrox is too dangerous. etc.

Then there are other people who have demonstrated their ability to function adequately in 180 feet and some a good bit deeper during many dives. Often times these individuals are not particularly, young, fit or strong.

I personally think there are huge discrepancies between different people and their susceptibility to narcosis and their ability to manage it. So maybe a more reasonable message is to progress past 100 or 130 feet very slowly and be super vigilant to avoid excessive strenuous activity (like dragging a diver up from the depths when he has completely lost situational control).

In any regard, the ability to navigate, control buoyancy, monitor air pressure and depth, keep track of a buddy etc. are all skills that must be totally mastered and must be over learned so that they are almost instinctive- BEFORE anyone should be trying to go deep.

Yes but....
Part of the problem is that the analogy with being drunk is faulty. Narcosis is its own kind of impairment, so trying to say, "I didn't feel a buzz" is not useful info.
These are NOT new messages; they have been the same for years and years.
But new people keep learning them for the first time....

 

[northernone]

These kinds of stories really scare me. The variability between individuals who can and can not function at depth is dramatic.

120 feet is NOT deep from my personal perspective on narcosis, but for that individual - on that day- it certainly was.

The message to new divers is very confusing:

• divers are drunk and they don't know it,
• divers who say they are acclimated (to depth) are foolish and delusional,
• diving past 100 on air or nitrox is too dangerous. etc.

Then there are other people who have demonstrated their ability to function adequately in 180 feet and some a good bit deeper during many dives. Often times these individuals are not particularly, young, fit or strong.

I personally think there are huge discrepancies between different people and their susceptibility to narcosis and their ability to manage it. So maybe a more reasonable message is to progress past 100 or 130 feet very slowly and be super vigilant to avoid excessive strenuous activity (like dragging a diver up from the depths when he has completely lost situational control).

In any regard, the ability to navigate, control buoyancy, monitor air pressure and depth, keep track of a buddy etc. are all skills that must be totally mastered and must be over learned so that they are almost instinctive- BEFORE anyone should be trying to go deep.

I'm in agreement. Onset and symptoms are so highly variable between divers it seems and bites differently on different days even. Mastery of skills is critical before going deeper.

The adage from the riggers in the music industry comes to mind as well: "If you can't do your job safely when drunk you're not fit to do it at all."

Cameron

 

[dave22387]

Narcosis is a funny and scary thing. I used to dive deep on air and loved it. I would get to the bottom and feel like King Neptune... I enjoyed to buzz when I noticed it. I dove like this for years until one day I had a problem (maybe 15 years ago). I was chasing a fish to shoot and all of the sudden I had a mouth full of water instead of gas. Instead of switching to number 2 which was literally on my chin and I thought instinctive, I tried to suck on the reg again and again and got more water. Then I realized I guess once I was in dire need of air that I had another regulator. I told my body to switch over but it just wouldn't do it. At that point, I don't really remember switching over to my second reg but I obviously did at some point. At that point in my diving career, I was doing technical dives and I knew my gear intimately and had done hundreds of S-drills and Valve drills. My brain just wasn't working... Basically, I was lucky that I somehow or someone made me switch to my secondary. I would have surely drowned because my brain wasn't working. I thought that I could "manage" my narcosis but that experience which truly shook me up taught me a lesson. It's like when you're sitting at a bar and drinking like a fish you don't notice it. But when you get up to go take a leak... Here comes the floor... That being said when you get off of the bar stool while 150 down you may not be so lucky... If you want to go down on air make sure you have somebody competent with you and preferably they have some He.

I still do deep air sometimes but the conditions and the dive has to be correct. I had a discussion with John Chatterton (Shadow Diver) about Narcosis and he is a firm believer that Narcosis and CO2 are related which I agree. If I am going to dive without He, It will be a dive with absolutely 0 stress, warm water, and very very minimal exertion. No penetration, currents, or anxiety. If any of those situations exist or if I don't have a buddy, Helium is on board.

If you haven't read this before give it a read. Diving with Stevie Wonder

 

[MaxBottomtime]

On the other had, John Chatterton explains here how he was able to make a penetration dive on the Andrea Doria on air.

 

[johndiver999]

Narcosis is a funny and scary thing. I used to dive deep on air and loved it. I would get to the bottom and feel like King Neptune... I enjoyed to buzz when I noticed it. I dove like this for years until one day I had a problem (maybe 15 years ago). I was chasing a fish to shoot and all of the sudden I had a mouth full of water instead of gas. Instead of switching to number 2 which was literally on my chin and I thought instinctive, I tried to suck on the reg again and again and got more water. Then I realized I guess once I was in dire need of air that I had another regulator. I told my body to switch over but it just wouldn't do it. At that point, I don't really remember switching over to my second reg but I obviously did at some point. At that point in my diving career, I was doing technical dives and I knew my gear intimately and had done hundreds of S-drills and Valve drills. My brain just wasn't working... Basically, I was lucky that I somehow or someone made me switch to my secondary. I would have surely drowned because my brain wasn't working. I thought that I could "manage" my narcosis but that experience which truly shook me up taught me a lesson. It's like when you're sitting at a bar and drinking like a fish you don't notice it. But when you get up to go take a leak... Here comes the floor... That being said when you get off of the bar stool while 150 down you may not be so lucky... If you want to go down on air make sure you have somebody competent with you and preferably they have some He.

,,,,

If you haven't read this before give it a read. Diving with Stevie Wonder

We should avoid deep dives on air with buddies who are also on air, but instead find people using helium to watch us?????

I think that is a tough sell... Imagine the discussion with a prospective buddy who is a mix diver.

 

[northernone]

We should avoid deep dives on air with buddies who are also on air, but instead find people using helium to watch us?????

I think that is a tough sell... Imagine the discussion with a prospective buddy who is a mix diver.

"The designated diver"

I'll do it... if you pay my mix and cover a second dive where I don't have to watch you.

(As a deep air diver if ever I'm considering I may need a safety diver to monitor my stupidity5 I am switching to trimix for the dive)

 

[boulderjohn]

The story of an event in Cozumel is an important one for this topic. When the story was first reported, it was a tale of 3 divers caught in a serious down current, but eventually the truth came out. A dive shop owner, one of her DMs, and her boyfriend planned a single tank bounce to 300 feet. At 300 feet, she was so thoroughly narced that she continued going down. The DM caught up with her at 400 feet and turned her around. Fortunately, the boyfriend had stayed at 300 and had a larger tank, because they were able to do a 3-person buddy breathe when the owner and DM ran out of gas during the ascent. It was not enough gas to do deco stops. The dive shop owner died after extensive hyperbaric treatments, and the last I heard the DM will never walk again.

Here is the thread: Scuabamau diving accident

 

[boulderjohn]

I dived the wreck of the San Francisco Maru in Chuuk before I had any technical training, reaching 181 feet in the hold. I felt perfectly fine--not a hint of narcosis. After the dive, I realized something was not right--we had been told there were land mines on shelves in that hold, but I was in the hold, and I had not seen any. I was very disappointed. Then I saw the film one of our divers had made of the dive, and, yep, there were the mines, in perfect sight. I was swimming right next to that videographer when he shot the film.

 

[dave22387]

We should avoid deep dives on air with buddies who are also on air, but instead find people using helium to watch us?????

I think that is a tough sell... Imagine the discussion with a prospective buddy who is a mix diver.

It is a very tough sell. I was just saying if the OP wanted to see what it was like.

 

[drbill]

As a marine biology and videographer, I spent a few years doing deep air dives (max depth 200 fsw). I initiated this period by slowing increasing my maximum depth over a period of months until I was able to reach my max. I was doing 300-350 dives per year during this period.

I rarely felt any significent signs of narcosis. One of the ways I judged that was my ability to locate, frame and follow the subjects I was filming. I also monitored my gauges (far more frequently than I would at shallower depths). I really feel that my frequency of diving made my body more tolerant of nitrogen. About a year after I stopped doing this, I was very significantly narced on a dive to 151 fsw and later noticeably narced at 107 fsw.

I do consider this an unusual situation though and wouldn't expect it to translate to other divers.