Basic narcosis questions

[stanw]

How far down do you need to go before narcosis could become a factor? What factors, if any, can contribute to one person being affected by narcosis while someone else is not?

 

[Dive Junky]

How far down do you need to go before narcosis could become a factor? What factors, if any, can contribute to one person being affected by narcosis while someone else is not?

If you are gonna get hit by it, it usually strikes approaching 80 ft or so. What causes someone to be effected by Narcosis is not really understood. I will say however that I have noticed on my very deep dives over 130' that descending slower does help me keep my wits better.

 

[stanw]

So would it be accurate to say that narcosis is not likely to be a factor in water 70-ft or less? I do not think I am going to likely be going further than that.

Thanks.

 

[LeadTurn_SD]

Everyone is different as far as narcosis effects go. When does it become a "factor"? I've read / heard various answers, but I think many(?) will start to actually notice the effects in the 80-100 foot range, give or take. A lot depends on the individual, water temperature and viz, etc. It can also vary day to day with the same individual.

Noticing the syptoms of narcosis and being impaired are two different things... I think for a lot of us impairment can begin before we recognize the symptoms (my wife will tell you I'm impaired at 1 atmosphere ).

Many divers continue to function well at depth despite narcosis. I'm not one of them.

Personally, I'll begin to recognize the symptoms of mild narcosis at around 100-120 feet, and beyond 150-160' (on air) I'm feeling fairly impaired: Not hallucinating or in a total stupor, I just feel mentally "slower", less able to solve problems. Sort of like having a couple stiff drinks, and realizing I'm sort of mellow and "buzzed", but not yet falling-down intoxicated. That's the closest I can describe the sensation. Deeper depths (for me below 150') on air: I don't remember much about the dives, but do remember feeling paranoia and something like tunnel vision (not a true loss of vision, but a loss of awareness of anything that was not right in front of my face). That is REALLY scary. This is all from the '70's and '80's for me.

It has now been over 20 years since I went beyond 100 feet, and I'd guess my "impairment depth" is a certainly shallower than when I was in my teens and twenties.

Not sure if this answers your question. I'm sure others will have some good responces.

Safe Diving!

 

[Cave Diver]

How far down do you need to go before narcosis could become a factor? What factors, if any, can contribute to one person being affected by narcosis while someone else is not?

So would it be accurate to say that narcosis is not likely to be a factor in water 70-ft or less? I do not think I am going to likely be going further than that.

Thanks.

Narcosis seems to affect people differently and at different depths, just like alcohol does. Whether it would be accurate to say you won't feel the effects at 70' is just conjecture.

Most people dont feel obvious signs of it at that depth, but that's not to say there isn't some impairment, or that it may affect you differently.

Rapid descents, dark (low viz) or cold water seem to increase the onset of narcosis in some people.

Narcosis makes some people happy, some paranoid, and some it just seems to dull their senses and kills awareness to their surroundings.

If you have concerns about it, I would suggest diving first with someone that has experience under the conditions you plan to dive until you know how you'll react.

 

[Dive Junky]

So would it be accurate to say that narcosis is not likely to be a factor in water 70-ft or less? I do not think I am going to likely be going further than that.

Thanks.

Not likely. However remember breathing compressed nitrogen can always have a narcotic effect on us. There is also the martini effect or rule that was a general rule of thumb. For every additional atmosphere of pressure you put yourself under its like drinking another martini.

 

[Tortuga68]

Oxygen is also narcotic

LeadTurn's post sounds pretty accurate to me, based on my own experience - although I've also had "happy narc" at 50m, which is quite fun but equally dangerous since you may not pay as much attention to what you're doing as you should

Not being properly hydrated will increase the effects, and for me can make the difference between getting happy narc or dark narc

 

[Diveralan]

As many have said about 80 ft in about average, however everyone is different. Most of us know at least one person who can get drunk on one drink. Others who never seem to. I know one experienced diver who can't dive below 60ft, by the time she hits 70 she is in her own world and will just watch the fish with no sense of time.

Just as you can build up a resistance to alcohol you can build up a resistance to nitrogen. You should work up to deeper dives slowly. If you have never gone below 40 ft don't do a 100 ft dive. Do a few 60ft and 80 ft dives first. If you are planing a dive deeper than you have been before try and dive with a buddy who has experience at that depth.

 

[Cave Diver]

Oxygen is also narcotic

LeadTurn's post sounds pretty accurate to me, based on my own experience - although I've also had "happy narc" at 50m, which is quite fun but equally dangerous since you may not pay as much attention to what you're doing as you should

Not being properly hydrated will increase the effects, and for me can make the difference between getting happy narc or dark narc

Anectdotal evidence suggests that higher workloads and/or C02 retention may play a part in "dark narc" as well.

 

[PfcAJ]

Just as you can build up a resistance to alcohol you can build up a resistance to nitrogen. You should work up to deeper dives slowly. If you have never gone below 40 ft don't do a 100 ft dive. Do a few 60ft and 80 ft dives first. If you are planing a dive deeper than you have been before try and dive with a buddy who has experience at that depth.

Do some more reading. Academic reading. Alcohol 'tolerance' suddenly vanishes when presented with a novel situation. Same thing with nitrogen.

When things go south is when you start sliding down the slippery slope of the incident pit.