what is your take on this??

[pm3009]

This is the first time I've ever experienced this. I've been diving for about
4 years now. Around 110 dives. Advanced C-Card.

I was in Cozumel this past July with my friend and my cousin. We dove
Devils Throat one day. Had a great dive. Everything went smooth. Second time
I've dove this site. Dove it once 4 years ago and it also went smooth then. That site has been my two deepest dives to date. 133 feet the first time around. 142 feet this time around.

Towards the end of the week, my friend said she just didn't feel right. She said she had a nightmare, that she died diving. So, I told her she shouldn't dive if she doesn't feel right. She stayed behind, and I dove with my cousin. We went back to Devils Throat for the second time that week. We LOVE that site! Now when we dove it 4 years ago, we did a very quick swimthrough. This DM took us through some amazing swimtroughs this time around. I didn't know this site had so much to explore.

Anywhoo....felt very rushed getting ready on the boat and into the water and felt some anxiety for whatever unknown reason. For a brief second, the thought occurred to me as I was wondering why I felt anxiety...."what if my friend was really dreaming about me? what if I'm the one who dies on this dive?". Stupid I know.

So...as I'm descending, I'm trying to slow my breathing and relax. Swimthroughs have always been my favorite. We get to the swimthrough, and I'm just not feeling right. I felt like I was hyperventilating. And then the DM brings us deeper, and into a narrower spot. And I just felt like I couldn't catch my breath at all. I felt like I was overbreathing my regulator or something...I just couldn't get enough oxygen. I was in the rear. I felt extremely close to panic. I decided....ok....you have stop going through these swimthroughs,and just swim above them. I was about to do that, and I told myself....just stop being a baby....relax and breath slow. You must be just feeling claustophobic. So I continued and went through another swimthrough. And the feeling of panic was just getting worse. The feeling of not being able to get enough oxygen was just getting worse and worse. So as the DM and my cousin were going through another swimthrough, I was about to follow, telling myself to just relax and you'll be fine....you've just dove this site a couple days ago and loved it... and then I backed up and decided I had to ascend some, or something really bad was going to happen. I signaled to the DM that I was ok, but I needed to go up some. So I swam about 15 feet above them, while they went through another swimthrough, and we met on the other side. I didn't start feeling back to normal until I was about at 60 feet.

The DM asked me at the surface if I was ok,and I told him what had happened. He said that, that happened to him once, and that it was because he had gotten narc'd.
He said he just felt like he couldn't get any oxygen. He said that I did the only thing I could have, and dove shallower.

So...in your opinion....was I narc'd? Or was it just anxiety/near panic? Was I overbreathing my regulator because I was near hyperventilating? I did think to myself afterwards...wow...this must be how people can pass out and drown underwater with plenty of air in their tanks.

Went on to a shaller 2nd dive, and felt great.

Strange how I dove that same dive earlier in the week, and had a wonderful relaxing dive.

Bye
Pam

 

[partridge]

Personally I think it was narcosis. It affects people in different ways on different days. 142 is definitely narc territory.

For me, it starts by thinking about my family. Then I start thinking wow if I just spit out this reg I could never see them again. Been hit many times and always the same way. At least now I recognize it easy enough.

 

[pm3009]

Hi Paul, Did you feel it at all physically? I really feel, that if I forced myself to go through that last swimthrough, that I may have completely panicked or blacked out, and not be here today. Very scary feeling!

Personally I think it was narcosis. It affects people in different ways on different days. 142 is definitely narc territory.

For me, it starts by thinking about my family. Then I start thinking wow if I just spit out this reg I could never see them again. Been hit many times and always the same way. At least now I recognize it easy enough.

 

[pm3009]

Another question..... If you're just down at 130-142 for a minute or two, is it ok to be diving on air ?

 

[ParamedicDiver1]

Pam,
Here is my take on this. From what I have seen and read, Nitrogen Narcosis takes on several forms. One current therory on "NN" says a physiochemical interaction occurs between the inert gas and the nerve cell membrane. This occurs in the brain and interfers with the brain's ability to function normally. This usually manifests itself as difficulties with problem solving, apparent drunkenness, and object fixation. But I believe that a "panic-attack" type reaction is equally as possible. Another possibility is that you were already stressed, thinking about your friends dream, you were rushed on the boat...again more stress, and it kept building until you were in a panic situation. One thing to consider, you were able to focus and control yourself enough to ascend, so that gets a WTG from me.

Something else to consider, when you were breathing rapidly, you were probably hyperventilating, which is a problem. These quick, deep breaths reduce the level of carbon dioxide (CO2) in the blood. This reduced level of carbon dioxide causes the arteries to constrict, reducing the flow of blood throughout the body. When this occurs, our brain and body will experience a shortage of oxygen which is not good.

As far as the depth thing, standard wise (at least SSI) it was a little too deep, I am assuming your computer did not have to go into decompression mode. Some of the dive physics involved state that as far as oxygen toxicity is concerned, you were ok...that happens around 221 fsw. But DAN warns that heavy work can increase carbon dioxide retention and could produce oxygen convulsions at depths as shallow as 140 fsw. (fsw=feet sea water)

 

[Blitz]

You should be diving some kind of mix. I wouldn't recommend diving air that deep just because of the narcotic effect.

 

[partridge]

No I do not feel anything physically. But hard time breathing is started most of the time from psychological reasons. Then because you breathe too hard or not enough it gets harder to breathe..... It is a vicious cycle. The trick is to recognize it as soon as possible because it willlimit you physically. This means to get out of the situation before you are required to do anything. A buddy of mine could not even clear his mask because he was too narced.

That said, if available, I would do dives below 100 feet on some kind of mix. It will add to the bottom time as well.

 

[pm3009]

Thanks for your input Scott. I appreciate it. I didn't think that I was narc'd, because I wasn't confused during the dive. I was consciously trying to slow my breathing, and calm myself and had no problem focusing on my guages etc. So can narcosis make your body react that way, even though you aren't in a confused state?

Thx.
Pam

 

[Doc Harry]

Hi Pam,

I'm too am learning a lot myself about these issues. Let me share my limited knowledge.

Is it okay to dive on air at 140 feet? The short answer is that if you don't the answer, then you probably shouldn't be doing it. Especially at 140 feet.

What is the PO2 on air at 140 feet? What is your NDL at 140 feet? Have you done any "rock bottom" calculations with your dive buddy to ensure you actually have enough gas for the dive?

The long answer is that the max P02=1.6 occurs at about 185 feet on air. However, nitrogen narcosis is usually the limiting factor. Many advocate limiting your nitrogen exposure to 100 feet on air (or to the nitrogen equivalent of 100 feet on air when using mixed gases). I believe that Dick Birch holds the world record for a dive on air (over 400 feet deep). I haven't calculated the PO2 at that depth, but I can tell you that it is frighteningly high.

Also, 140 feet is pretty deep. Have you done any "rock bottom" gas calculations with your buddy to ensure you have enough gas should one of you have catastrophic gas loss at depth? I usually switch to an AL100 for deep dives (haven't quite made the jump to doubles).

Good luck, stay out of trouble.

 

[Lead_carrier]

Thanks for your input Scott. I appreciate it. I didn't think that I was narc'd, because I wasn't confused during the dive. I was consciously trying to slow my breathing, and calm myself and had no problem focusing on my guages etc. So can narcosis make your body react that way, even though you aren't in a confused state?

Thx.
Pam

Yes, narcosis doesn't cause everyone to react exactly the same, just as DCS doesn't show all the same symptoms everytime on everyone. I believe it was NN, even though you say you weren't confused.

You other question, is it safe to dive 130-140 on air? That depends on the individual. It will definitely limit your bottom time, using nitrox ( a very lean mix) would give you a little safety margin because of less nitrogen uptake at shallower depths. Short of using trimix, you're gonna get narced. It is just a matter of how much.