Narcosis rears its ugly head
William Trubridge writes:
After switching from the Minima to Kerian‘s fluid goggles and suddenly being able to equalise as deep as I cared to go, I decided to start
doing a few dives in Free Immersion to mix it up a bit from the CNF training.
A couple of attempts took me into the 3 digit numbers and suddenly a monster that I thought I had dealt with back in 2006 jumped out
from under my bed. Carbon dioxide narcosis can be a pleasant, relaxing and soporific sensation, but in it's most extreme cases it
becomes sun‘ea| and alarming. It is accentuated by the no-warmup style of diving that I employ as well as the lower light levels deep
down in the Blue Hole.
The general sensation is of becoming more and more detached from your body, and an affected vision which can become hallucinatìon.
On a recent dive during the ascent I am watching my hands come up past my face, grab the line, then pull past me as the other hand
crosses for its stroke. To relax I close my eyes... and see exactly the same thing. To make sure I squeeze my eyes closed so that I can
feel the eyelids pressing against each other, then open and shut them but it makes no difference to what I see, which is a hallucination
of what my body is doing.
Today I spent 14 below 100m, and when I turned I knew straight away that I was
in for a ride. Very quickly the narcosis became overpowering and for the first time I
won‘ied about a deep water blackout caused by excessive ppCO2. Slightly alarmed I
began pulling harder on the rope, ensuring at the same time that the rest of my
body is kept relaxed. At these depths if you panic and try to get to the surface as
quick as possible then you will use all your oxygen long before you even reach your
Now my vision is starting to white out completely, and this is something that I have
never encountered before, which worries me further still. Suddenly out of the
whiteness there is a human fonn, that of my safety diver Julie Gautier', and I
wonder if I am hallucinating that as well, then I am on the surface, recovering and
doing the safety protocol. The narcosis has stayed with me all the way to the
surface, and the whiteness that I thought was my vision closing over was just the
returning light of day.
I first experienced when I passed 60m CNF in Dahab in 2005. These days I have
done so many dives in the 80's that I don't experience narcosis until past 90m, but
it will be a while before I develop any kind of tolerance to the extreme level of
exposure I am experiencing in a 100m+ dive.
Guillaume Nery writes:
Narcosis in freediving can be our friend or our worst enemy. The first time I experienced this phenomenon was in VWT dive to about 80m
in 2001. At this period I was able to dive around 70m in constant and I decided to dive at least 10m deeper because I was assisted by
the sled and because I didn't have equalisation problems. I thought it wouldn't be a problem. But the depth is not just a question of time
and equalisation, it's also a problem of narcosis. This dive was one of my worst dives ever. At the bottom, it was as if the cable was
moving around, my mind was not clear at all and I was narked until the first breath.
Fortunately most of the time narcosis is a better experience. In CWT, I can feel it over the 80m when I am not that trained and over the
95/100m when I am close to a record or a competition. Narcosis is the salt of freediving Julie Gautier (girlfriend of Guillaume and
french record holder in constant weight -65m) says. I feel surrounded by cotton, I feel comfortable and I don't need to breathe. The limit
between good and bad narcosis is very thin so it‘s important to keep quiet and to appreciate this sensation. It's very hard trying to
understand the reason of narcosis. Why is it stronger today than yesterday? Why can it be stronger at a shallower depth? There are just
many reasons to explain narcosis: depth, time at depth, cold, fatigue, dehydration, etc etc..
The easiest way to avoid bad narcosis is to improve step by step, to respect the adaptation of your body and to listen to your sensations.
You guys stay safe down there! Will you be trying for the WR in FIM, Will? by DN on 2008-03-22 21:03:48
Stay alive, Will. You are mortal. rnrnPS. Haluccinating about Julie Gautier is totally normal. by Sebastian on 2008-03-27 04:51:24