Is the severity of narcosis greater when diving cold water?

[grantmac]

In colder water I'm wearing a drysuit and am generally less comfortable than I would be in the tropics wearing a 3mm. I don't usually notice the discomfort now that I'm diving dry 1-4 times a week, it's simply normal.
However narcosis makes me very aware of my body so I notice the discomfort in cold water. Likewise a drysuit involves a degree of higher task loading compared to that 3mm.

Am I more narked in the cold? Or simply more aware of the effects.
I'm sure it's the latter.

 

[Boarderguy]

No one ever feels a thing untill one has to think

Depending on how hot the drop is you can feel it. When I drop into 140 on a shot line I sometimes feel a warmth wash over me around 135 ish. Once that happens I relax and enjoy the ride.

I've swum in cold water and my breathing rate goes up. So it makes sense. Everyone feels the cold differently. I'm not sure in BM index makes a difference.

That is the initial shock response to getting in cold water. That doesn't last, and if it did then you've got other problems going on. Once you've settled in (a minute or two) your breathing rate returns to normal. Last night in 52° water I used about 2k psi on an HP100 that included 10 minutes between 105 and 115 and 50 minutes run time. I breathe the same in Hawaii.

 

[Bob DBF]

Depending on how hot the drop is you can feel it. When I drop into 140 on a shot line I sometimes feel a warmth wash over me around 135 ish. Once that happens I relax and enjoy the ride.

Divers that do deep air have their ways, most divers don't.

Last night in 52° water I used about 2k psi on an HP100 that included 10 minutes between 105 and 115 and 50 minutes run time. I breathe the same in Hawaii.

Mine is always the same also, my consumption is nothing to brag about, but I breathe to avoid CO2 hits, and I have.

 

[Wibble]

I've swum in cold water and my breathing rate goes up. So it makes sense. Everyone feels the cold differently. I'm not sure in BM index makes a difference.

Swum? As in swimming in cold water?

That is not diving in cold water. There’s a massive difference between swimming and diving, not least as you should avoid exertion whilst diving to conserve your gas if open circuit or keep CO2 in check if on a rebreather.

Swimming in cold water, aside from being an odd thing to do for pleasure, is about exercising to keep warm or doing short swimming sessions. There’s no constraint on gas supplies either.

Last week I did 7 days of 60m/200ft to 70m/230ft dives, each between 2h and 2h45 long submerged in cold water around 7C/44f on the bottom and the extensive decompression time at 12c/55f (max of 2h). I could only do that with the appropriate thermal protection (and a high proportion of helium to counteract the narcosis).


The dive profile, the blue line showing the water temperature

 

[Scubagermany]

CO2 levels may go up slightly with breathing rate

Co2 levels in your blood will go down with increased breathing rate....

 

[Bob DBF]

Co2 levels in your blood will go down with increased breathing rate....

Could be either. It depends on the size of the breath, not the frequency.

 

[Vitesse2l]

Seems like there are too many variables to make a consensus on the OP's question.

Like many others, I don't know I've been narced, but I'm sure I have. I do know there's no cold water shock when I dive since I'm dressed for the conditions. I might cool down during the dive though.

 

[Scubagermany]

Could be either. It depends on the size of the breath, not the frequency.

Hyperventilation will lead to lower CO2 levels!

 

[Cthippo]

I've been in cold shallow water that was so uncomfortable I was really fighting not to panic and bolt above the thermocline. Breathing was almost uncontrollable. This was not deep water amd narcosis was not a factor, but cold can definately affect you, and accentuate pre-existong problems.

Lesson learned, ALWAYS wear my hood!

 

[steinbil]

Hyperventilation will lead to lower CO2 levels!

Shallow breathing will lead to higher CO2 levels!