Question Ever experienced Nitrogen Narcosis?

[Wibble]

Narcosis: it's a thing...

Firstly, get yourself a chamber dive. Various recompression chambers do experience "dives". PADI even have a speciality course that'll count to your Master diver certificate. Went down to 40m/130ft/5ATA. They gave us some test papers to do at the bottom. We were all giggling like schoolgirls. I couldn't read my writing and got some amazingly simple arithmetic wrong. Off me face as they say in East London where we did the 'dive'. Even the chamber supervisor forgot to put the stopper on a plastic bottle of water (narked too).


I went for a dive with a mate in a deeper quarry. Was the second dive so the twinset had an air top on 32%, so around 24%. We dropped down into the deep end where the technical divers go. There's a little blue boat at around 50m/165ft/6ATA. I got to 45m/150ft/5.5ATA and was off my face. All I did was hang there alternatively looking at my depth and my SPG, then forgetting the depth, then forgetting the pressure. I was useless. My mate was pretty much the same but made it the extra few feet down to the blue boat; I can't remember what he did there, he was on his own. We ascended to the "plain" at 28m/94ft/3.8ATA and the narcosis abated.


Final example was a dive on nitrox to a wreck at 50m/165ft to the sea bed. I had a bit of a rich mix so kept to the deck at 45m/150ft. I felt off my face again, talking to the blennies and lobsters. Because of training and experience I didn't feel out of control. At least I knew I was under the effects of narcosis so wasn't going to attempt anything difficult.



Anyway, narcosis is a thing and getting yourself a chamber ride is a fun way of experiencing narcosis.

 

[Saltwater_Parrot]

Narcosis: it's a thing...

Firstly, get yourself a chamber dive. Various recompression chambers do experience "dives". PADI even have a speciality course that'll count to your Master diver certificate. Went down to 40m/130ft/5ATA. They gave us some test papers to do at the bottom. We were all giggling like schoolgirls. I couldn't read my writing and got some amazingly simple arithmetic wrong. Off me face as they say in East London where we did the 'dive'. Even the chamber supervisor forgot to put the stopper on a plastic bottle of water (narked too).


I went for a dive with a mate in a deeper quarry. Was the second dive so the twinset had an air top on 32%, so around 24%. We dropped down into the deep end where the technical divers go. There's a little blue boat at around 50m/165ft/6ATA. I got to 45m/150ft/5.5ATA and was off my face. All I did was hang there alternatively looking at my depth and my SPG, then forgetting the depth, then forgetting the pressure. I was useless. My mate was pretty much the same but made it the extra few feet down to the blue boat; I can't remember what he did there, he was on his own. We ascended to the "plain" at 28m/94ft/3.8ATA and the narcosis abated.


Final example was a dive on nitrox to a wreck at 50m/165ft to the sea bed. I had a bit of a rich mix so kept to the deck at 45m/150ft. I felt off my face again, talking to the blennies and lobsters. Because of training and experience I didn't feel out of control. At least I knew I was under the effects of narcosis so wasn't going to attempt anything difficult.



Anyway, narcosis is a thing and getting yourself a chamber ride is a fun way of experiencing it.

I was actually just looking at one of these near where I live. To be honest, I was a little bit unsure of it, but it sounds like a pretty useful experience. My main concern is (though Ive personally not had this issue so far ), what if someone is having trouble equalizing? Obviously, you cannot just "go up" -- so does the chamber tech ensure that everyone is good before continuing pressurization and can they slow or stop the pressurization if that were to happen? Also - how quickly is pressurization (ie. like a slow descent, medium, very fast, incremental vs steady rate, etc)?

My deepest dive so far has been 86ft (nitrox), so definitely not in the overly susceptible range, and I definitely wasn't narc'd.

 

[wetb4igetinthewater]

Are you sure your buddy didn't think you were using your light to point something out? I have noticed that time perception can change with NN so your perception of a rapid torch movement could be perceived as a scanning or pointing action.

It was going in a circle. This was Lake Crescent. Other than two cars wrecks, there is nothing of interest.

If I was pointing something out, my light would go up and down to get his attention and then light up whatever I'm trying to point out.

 

[Gandalf-the-Diver]

Firstly, get yourself a chamber dive.

Where I am, there is a chamber the military uses, and civilians are not allowed in it. There is a chamber in Vancouver, which is for medical emergencies. If here in Victoria, and one has DCS, a helicopter takes you to Vancouver for a chamber ride. There are no chambers, one can go to do a test dive. A dive buddy of mine, once had the free Helo ride to Vancouver, for a chamber session. He said it skimmed the water all the way to Vancouver.

 

[Wibble]

I was actually just looking at one of these near where I live. To be honest, I was a little bit unsure of it, but it sounds like a pretty useful experience. My main concern is (though Ive personally not had this issue so far ), what if someone is having trouble equalizing? Obviously, you cannot just "go up" -- so does the chamber tech ensure that everyone is good before continuing pressurization and can they slow or stop the pressurization if that were to happen? Also - how quickly is pressurization (ie. like a slow descent, medium, very fast, incremental vs steady rate, etc)?

It’s fine. They take great care to ensure everyone inside can equalise. The pressurisation is slow and you quickly get used to it

My deepest dive so far has been 86ft (nitrox), so definitely not in the overly susceptible range, and I definitely wasn't narc'd.

Don’t get too hung up with narcosis. Whilst it’s effect is obvious when deep — beyond recreational diving depth limits — it is not really an issue when shallower.

The main mitigation is training, practice and experience. This means you are tuned in to notice issues and can deal with them efficiently. For example dangling kit, drifting away from the crowd, buoyancy, etc. it’s just the same as consuming a small bottle of beer; not an issue.

 

[Eric Sedletzky]

That's why a lot of inexperienced deep divers finish their descents with a full on crash into the bottom.

You mean like this?
The common practice of gross overweighting doesn’t help either.

 

[boulderjohn]

You mean like this?
The common practice of gross overweighting doesn’t help either.

Very much along those lines.

In some environments you can tell that the people descending ahead of you have reached the bottom when you see a silt explosion similar to this.

 

[BlueTrin]

One of the characteristics of narcosis for most people is they have no sense that they are experiencing it. I am one such person. I have never felt any different in situations where narcosis would be expected, but I have had clear and unmistakable evidence of narcosis on several occasions when I felt perfectly fine. In those situations, something has to happen requiring action on your part, action that is clearly subpar. If nothing like that happens, you can be narced and never know it.

Having to lay on the inflator hose to get neutral while deep has nothing to do with narcosis. It is a natural consequence of Boyle's Law. At 135 feet the air in your BCD is compressed 5 times what it would be at the surface, so you have to add that much more air to become neutral at that depth.

Is there a correlation between feeling narcosis and being narced more?

I definitely know I am narced if I go at 45m on air/Nitrox.

 

[boulderjohn]

Is there a correlation between feeling narcosis and being narced more?

.

I have no idea.

 

[stretchthepenn]

In some environments you can tell that the people descending ahead of you have reached the bottom when you see a silt explosion similar to this.

You just described my experience at the Blue Hole in Santa Rosa, NM. I was one of the first divers in that morning, hanging out and enjoying the crystalline water, when a n00b came hurtling past me, bottom-bound, and smacked the dirt. Aaaand there went the viz for the entire day...