First dive to 30m and narked out of my wits

[Puffer Fish]

Humm... I guess it is possible that you were narc'ed but that sounds a lot more like several other gas related issues. If I had those symtoms, I would be having the tank analyzed. With the concern that bad gas effects will increase with depth.

It is possible that you are hyper sensistive to Narcosis, but your description or tunnel vision would have me looking elsewhere.

 

[rawls]

It is possible that you are hyper sensistive to Narcosis, but your description or tunnel vision would have me looking elsewhere.

I have to agree with Puffer Fish. There are outlying factors that increase your susceptibility to narcosis such as medications, drinking alcohol, stress, sickness and dehydration, but it seems like 30 meters would put you in a category of being extremely hypersensitive to narcosis. Perhaps in knowing you were going deeper than your comfort level allowed caused the perceptual narrowing that you experienced secondary to possible anxiety you may have felt. The symptoms were relieved as you began to ascend which could equate to you getting more into your comfort range. I could very well be wrong but it has always been my understanding that the shallowest depth for experiencing narcosis is 33 meters/99 ft. In any event I am glad you are ok and regardless of what the problem was, you handled it well. Congratulations and thanks for the post.

 

[Tigerman]

I have to agree with Puffer Fish. There are outlying factors that increase your susceptibility to narcosis such as medications, drinking alcohol, stress, sickness and dehydration, but it seems like 30 meters would put you in a category of being extremely hypersensitive to narcosis. Perhaps in knowing you were going deeper than your comfort level allowed caused the perceptual narrowing that you experienced secondary to possible anxiety you may have felt. The symptoms were relieved as you began to ascend which could equate to you getting more into your comfort range. I could very well be wrong but it has always been my understanding that the shallowest depth for experiencing narcosis is 33 meters/99 ft. In any event I am glad you are ok and regardless of what the problem was, you handled it well. Congratulations and thanks for the post.

There is no absolutes with narcosis as it depends on a lot of factors, but being narced in shallower water than 25 meters is fully possible. Its however more likely in cold water with bad vision while fighting a current than it is drifting along in the caribbean..

 

[eponym]

Iamasmith, it's common to see narcosis spoken of as starting at "around 100 feet."

[ . . . ] it seems like 30 meters would put you in a category of being extremely hypersensitive to narcosis. [ . . . ] it has always been my understanding that the shallowest depth for experiencing narcosis is 33 meters/99 ft.

Albert Behnke and his associates at Stanford found early on that susceptibility to narcosis varies among individuals, with some getting narked shallower. I've seen marked narcosis in my advanced students at eighty feet.

According to articles at Scuba-Doc.com, narcosis is potentiated (enhanced, strengthened) by increased CO2 levels, as higher levels of CO2 affect the function of the brain's neurotransmitters. This is my own direct experience--working hard (or breathing shallow) can build up CO2 and create a dark nark at depths where narcosis would not ordinarily be a problem. I would not assume "extreme hypersensitivity" but rather concentrate on reducing stressors and activity at depth--gradually, as you yourself said.

-Bryan

 

[TSandM]

I have frankly hallucinated at 100 feet. I don't think one has to invoke any other explanation for the OP's symptoms. Perceptual narrowing is a classic symptom of narcosis. Some people are more susceptible than others (I say, as one who is very susceptible).

 

[iamasmith]

Thanks for all the feedback folks.

When I did my advanced O/W I definitely experienced some Narcosis effects at 23m!, it took me an extra minute to do a dive plan.. I looked up the table... got all the figures in my head and then didn't know what to do with them

I'm guessing that if Narcosis hadn't been coming on from earlier in the dive I might have challenged my buddy about how deep we were going. I think it was there from earlier and just got dark on me when I hit 30m.

Also, as I mentioned I do have a large lung capacity and I am still learning optimum bouyancy control - a deep breath at 15m gives me good lift over an obstacle. I think for that reason that I possible wasn't taking full deep breaths which I'm guessing means that I wouldn't be exhausting as much CO2 as I would on surface.

It all fits and all makes logical sense to me and thanks for all the info folks. Rationalising it doesn't mean that I'm not going to be more cautious in future. I don't really want to dive straight into a similar or worse situation in the future and I guess I need to just experience what my breath control does to bouyancy without the expense of amassing CO2.

Regards,

-Andy

 

[evil_xander]

Just breathe normally, try to relax and not think about your breathing pattern.

The worst case of narcosis I experienced was when I experimented with my breathing pattern, slow & long breaths with poor execution and etc - CO2 buildup par excellence.

I laughed my ass off for a minute or so, it all went away when I went just a tad more shallow. This all occured at some 30m. Never happened again, at least didn't manifest itself like that.

 

[rawls]

Appreciate the feedback on the depth issue folks...always learning....Thanks!!!

 

[BDSC]

I have to agree with Puffer Fish. There are outlying factors that increase your susceptibility to narcosis such as medications, drinking alcohol, stress, sickness and dehydration, but it seems like 30 meters would put you in a category of being extremely hypersensitive to narcosis. Perhaps in knowing you were going deeper than your comfort level allowed caused the perceptual narrowing that you experienced secondary to possible anxiety you may have felt. The symptoms were relieved as you began to ascend which could equate to you getting more into your comfort range. I could very well be wrong but it has always been my understanding that the shallowest depth for experiencing narcosis is 33 meters/99 ft. In any event I am glad you are ok and regardless of what the problem was, you handled it well. Congratulations and thanks for the post.

I too would agree with you and Puffer Fish. I have recently looked at several studies that have been done on Narcosis both in actual diving conditions and in chamber conditions and what you have said about the 100ft depth(give or take a few feet) is what the studies revealed. It is possible that certain individuals based on the factors that you mentioned above could experience symptoms of narcosis at depths of less than 100ft but that would be the exception and not the rule. I also saw a study (it may have been referred to in the thread) where divers were split into three groups before a dive. Basically one group is told they are very likely or certainly are going to experience narcosis, the second is told less so, and the third is told even less so. All go on the same dive and guess which group reports having the most severe symptoms of narcosis. Yep. The first group. That's not to say they didn't actually experience narcosis, but it does suggest to me that the mind may play as big a role in what we perceive as symptoms of narcosis as the actual physical state of narcosis itself.

BDSC

 

[wedivebc]

I could very well be wrong but it has always been my understanding that the shallowest depth for experiencing narcosis is 33 meters/99 ft.

Wrong on two counts, I have personally felt narcosis shallower than 99ft and 33 meters is 109ft not 99ft