Does cold water narc you more?

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jtivat

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Scuba Instructor
Divemaster
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Location
Michigan, Grand Rapids
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At the same depth lets say 100' would you get more narced in 45 degree water than in 65 degree water or would it be the same?
Thanks
 
narc you in the physical sense of affecting the nitrogren narcosis, I don't think so.

Affect your thinking etc as you're half focused on the cold rather than what's at hand, absolutely - if you're cold.
 
based on very few data points 'cause I'm still a noob but...

Have to say it matters more if *you* are cold, not what the water temperature is. The diver I helped haul off a 95' sloping bottom in Lake Superior a few weeks back was badly underdressed for the 39F water - and narced *stupid*. (He was shaking uncontrollably but unaware that he was cold or how deep he was - fortunately he was a compliant little narced iceberg and didn't fight me). Quote " but I was at 130' just last week <back in Florida> and I wasn't narced then".

Neither his buddy, who had a different cold-water problem to solve but was appropriately dressed, nor myself nor my buddy (also appropriately dressed) showed appreciable signs of narcosis (though it was probably there and we were simply too busy to enjoy it). Damn good thing too.

One of the local divers, a man with 30+ years cold water experience, told me he'd been narced at 60' once - he'd let himself get cold and tired. JMO - Cat

Edited to add: before someone jumps the gun and says "he wasn't narced, it was just the hypothermia" I should add that his brain kicked out of neutral again at about 40' - and there was *no* difference in water T between 95' and 40' that day
 
Good question JTivat and something I was wondering myself while up in Tobermory a few weekends ago in water at 39 F. My personal observations tend to concur with Cat's as well.

In Carl Edmond's book "Diving and Subaquatic Medicine" there is only one reference to cold and nitrogen narcosis.
"Other factors have been observed to effect the degree of narcosis. Alcohol, fatigue, anxiety, cold, reduced sensory input, and oxygen and carbon dioxide disturbances are interrelated in impairing the diver's undererwater ability."

In Cat's diver above from Florida there may have been a few of those factors like fatigue (traveling), anxiety (new dive environment), cold (Lake Superior is always cold and if the diver does not have proper thermal protection his core will cool quickly), reduced sensory input (diver having to wear hood and gloves), and CO2 disturbances (anxiety may cause faster shallower breathing with increased pp of CO2 which is additive to the increased N2 tension effects) which all acted to predispose the diver to nitrogen narcosis in the cold water whereas at the same depth in warm water he was fine. Last summer I witnessed a similar scenerio in a visiting diver from Brazil who became quite narced in 80 foot cold Toby water. Likely was multifactorial as well with regards to the cause. I wonder if research has been done on narcosis using dry hyperbaric chamber dives, cold ambient air, rectal temp probes and all?

As for the effects of narcosis though on hypothermia Bennett and Elliot's "Physiology and Medicine of Diving" states, " this study proved conclusively that divers breathing compressed air are predisposed to hypothermia, due to the inhibitory efffect of inert gas narcosis on shivering." In other words the increased ppN2 inhibits one's ability to raise core temperature by shivering which further increases a diver's risk of hypothermia.

It appears then that the diver above was likely in a dangerous positive feedback loop whereby his poor thermal protection and other factors allowed him to become 'narced' and this narcosis impaired his shivering thermogenesis response which then further worsened the narcosis. Thermal perception according to Bennet is also severely blunted by high N2 levels. The only way out of this lethal loop was to immediately lower his exposure to high partial pressure of nitrogen by moving him to a shallower depth.

Had it not been for this diver's very attentive properly dressed buddies he likely would have carried on merrily down the slope only to disappear out of sight permanently.
 
One of the things I have noted is that when dropping through a thermocline into mid 40 degree water at 60 feet or so in a wet suit is that I feel the cold, and if I stay at this depth a few minutes I STILL feel the cold on the exposed parts of my face, so it is not just an issue of adjusting to the colder water. However if I continue down to 120-130 feet, I no longer feel the cold on my face when I get there. It's my opinion that a bit of nitrogen narcosis makes you feel nice and toasty while the cold water is at the same time potentially sucking the life out of you.

Consequently, I limit my bottom time down deep to 15 minutes or so and I don't skimp on accessories like a good hood/vest combination and good gloves when diving deep as I think the effects of nitrogen narcosis do leave you at greater risk of hypothermia, or at very least at a greater risk of not recognizing the onset of hypothermia.
 
I have been to depths in both warm and cold water and have never felt narced (I'm sure I was, especially past the 130' mark) but I can see where it would be worse in cold water. You loose a lot of dexterity with gloves, and find a wetsuit slightly more distracting than diving without. Although this is nothing more than speculation, I would think that cold water would bring on narcosis faster.
 
Hello! I am new here.I only dove warm waters for my open water checkouts.Otherwise Lake Michigan and Superiour is where i like to be.I only have a little over 30 dives logged,3 over 100 feet,so I am very cautious that deep.I think the narcosis affects me making me a little paranoid.I overcome that by flooding my mask and clearing it when I feel a little nervous,I don't know why but that action calms me down and I continue with dive.I don't know if I was any help,I just wanted to say what works with me.
 
Personally,

I think anyone who jumps into 39F water is showing signs of being narced BEFORE they even get in the water...but thats just because I live in Florida now.

Just kidding!!! You guys enjoy your cold water and I will enjoy my warm water!
 
Did a test with a dive buddy of mine a few year back.

Went to 145 in 42 degree water.I was on trimix,him on air. He looked like a drunkin fool and I felt like I was back at 70.

I believe it is a perceived thing. Been down past 200 in warm water and did not notice a difference from 80.Would have like to have done trimix as a comparison there. You have to be hammered.

Ron
 
I just got back from Tobermory (awesome diving up there). After feeling a light bit of narcosis at 122 ft. on a wreck up there, I will admit that a colder environment seems to predispose me to inert gas narcosis.

I was down to the same depth in Provo and never felt any different than I did at 20 ft. When I go deep in cold water, it seems to be more of an issue for whatever reason and something that I keep a close eye on. BTW, I do wear a drysuit in that enviroment and am not actually cold in the water. Maybe it is the extra task loading or something, I don't know.
 
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