narcosis

[Sohum]

I am fresh to this sport. I have not yet dived to depths at which I could experience narcosis. I was wondering if narcosis whilst freediving was similar to the experience whilst scuba diving? I have dived deep with scuba (60m) on air and narcosis was a very pleasant feeling. most threads related to narcosis and freediving on db relate it to a feeling of anxiety and so it seems to be a being a limiting factor to their performance.

Also- I have noticed while diving on scuba that tolerance to narcosis increases rapidly after doing several deep dives on a short term basis. Is this true while freediving as well?

please share,

Cheers,
Sohum.

 

[efattah]

Freediving narcosis can be pleasant when diving for fun. In cold dark water, diving for fun with significant bottom time, narcosis appears at the same depth as for scuba diving (35-40m).

Diving on a line, narcosis appears deeper (60m+ or more), and generally it is not so pleasant since you are really focused on the challenge of the dive. It can be okay if you are going to a conservative depth but on a full max you really wish you could just concentrate on swimming, but at very deep depths (90m+) the act of swimming becomes more difficult since narcosis can make motor control of the body much harder. It can feel kind of like when your legs are 'asleep', you must think very hard to make them move.

 

[Sohum]

Hi Eric,

So basically its the same feeling in scuba, rec. freediving and line freediving, only its the circumstance which makes it different right? Also then it must be that the problem would only set in during the ascent, and the free fall would be very relaxed because you are not making any attempt to move?

thanks for replying

 

[efattah]

Narcosis usually hits me around 75m on the descent while sinking. After 95m it increases incredibly fast and my vision gets all 'white and fuzzy' and my head starts buzzing. Then on the ascent CO2 is generated which compounds both the O2 and N2 narcosis. So I would say on the descent you have N2 narcosis, and on the ascent you have CO2 narcosis, N2 narcosis and O2 narcosis. On a deep ascent the narcosis feels different than scuba because you have O2 and CO2 narcosis which you do not get on a scuba dive. These can create a profound feeling of fear/panic and a feeling of impending death (i.e. a feeling that death is imminent and that you have absolutely no chance to make it to the surface alive). With experience you can learn to ignore this feeling. But it is imperative that you start the ascent in a positive state of mind.

So on a recreational dive to 40-50m the narcosis feels like scuba. On an 80m+ dive the narcosis is different.

 

[Sohum]

A narcosis cocktail. I wonder if the fear does anything to sharpen the dive reflex as I read on an article by sebastien murat. Does tolerance to narcosis increase after a few days of diving deep?

Thanks for taking the time eric.