I want to get narked

[mattvish]

...to get to know my limits and observe my reactions. Wouldn't it be useful to have this awareness? There are large hyperbaric chambers, HBOT have many therapy application, and apparently, it's possible to get rides Drunk Divers. I mean, that looks seriously fun. Somebody should set one up at DEMA and sell tickets

I do go to 40m (OC air) and have never experienced (or noticed) any narcosis in 30 years of diving. Not that I'm planning to go much deeper on air, I know that there also other factors and certainly don't want to trigger another deep air discussion here. I'm more interested in whether this experience is transferable to actual personal diving limits.

 

[Nick_Radov]

Ever been on nitrous oxide at the dentist? Same effects from N2O on the surface as plain nitrogen at depth.

The subjective experience of narcosis can be more heavily impacted by CO2 level than by depth per se. This is difficult to simulate in a consistent manner because it depends on exertion level and individual physiology, although the increased gas density at depth does make hypercapnia more likely by increasing WOB.

 

[OTF]

I second that the few times I've been properly narc'd the feeling instantly reminded me of being a kid at the dentist. PERSONALLY I don't notice it until about 140ft, though I'm sure testing would show effects start much shallwer. Some days when I try to do math, write a legible page of notes, or find that damn shackle pin that was just in my hand I wonder if it has a slight effect starting as shallow as 60ft... Anyway I don't dive deeper than ~130 without helium anymore anyway.

I've heard that the best way to experience what you're looking for is to dive relatively deep on air, take note of your feelings/surroundings and maybe do a basic mental/fine motor challenge, then switch to a bottle of helium-rich trimix and note the surprisingly significant differences as the world clears up where you didn't even realize it was foggy. Of course this is a technical dive that should only be undetaken with appropriate training and safety precautions.

If anyone knows how to get a "for fun and science" dry chamber ride in the USA I would be seriously interested. Only heard of outfits offering that in Europe. The effects seem to be very different in a dry pot vs. actual diving.

 

[Vitesse2l]

At 30m+ you make good decisions slowly, much more than 40m and it's making bad decisions fast. Or so I've been told. That would apply to cold UK waters with low viz. I understand that conditions affect the feeling of being narked too.

A friend diving air tried a few breaths of a helium mix on a dive and described the feeling as like having a cool wave of clarity passing through, which went away once back on air. It'd be fun to try it in a chamber.

 

[boulderjohn]

The effects of narcosis are neither consistent nor predictable.

A friend of mine, a tech instructor, said his worst narcosis experience happened on an NDL dive at about 85 feet. It was a dark narc, a sense of impending doom. He rose about 15 feet for a minute or so, and it went away. He resumed the dive without an issue. He has never had any other experience like it.

For me personally, I don't really feel anything, and my only clear narcosis experiences were when something happened during the dive to make me realize I was being even more stupid than normal. Had those experiences not happened, I would have had no idea the degree to which I was narced. I assume I have been similarly narced on other dives without being able to tell.

When I was a student in an early tech class, my instructor had me switch between air and trimix at depth so I could see the difference. I couldn't see any difference at all. When I was later an instructor, a student asked me if we could do it, and he said he could tell a big difference. Again, I didn't feel a bit of difference.

 

[rjack321]

I'm more interested in whether this experience is transferable to actual personal diving limits.

It's not transferrable:
1) its a dry chamber
2) you're sitting there not working

 

[Green Frog]

I have to say everyone is likely to be affected differently even the same person on different days under slightly different conditions. When I took my original PADI AOW course they made us perform simple tasks at about 20 m or less to see how the depth was affecting you. We went by the “2 martini” rule, that the effect of each 20 meters of depth would, on average be the equivalent of 2 alcoholic drinks. Different people perform differently under the influence of alcohol as well as narcosis. If you did well @ 40m, you handle your nitrogen well, or perhaps you were narc’d and weren’t aware of it.

 

[SpeedyJ]

I had never been narc'd until I started diving trimix... or said another way, I didn't realize how narc'd I was even at relatively shallow depths until I started diving trimix.

Unfortunately, we're not good at judging just how impaired we are when we're impaired. At 140' on air, I'm willing to bet you're impacted by narcosis. I now know I was when I used to do 140' dives on air.

 

[BRT]

I am affected before I get to 100'. It is hard to define, but I can't trust my decision making abilities. A buddy came up to me and showed me his dead computer. I carry an extra just for that purpose. (Yes I know our profiles were not exactly the same) But at depth it did not come to my mind to give him my spare until some time had passed.

 

[GiraffeMarineSalvage]

I do go to 40m (OC air) and have never experienced (or noticed) any narcosis in 30 years of diving. Not that I'm planning to go much deeper on air, I know that there also other factors and certainly don't want to trigger another deep air discussion here. I'm more interested in whether this experience is transferable to actual personal diving limits.

Simple test on your next deeper dives: take a dive slate and write out some basic math problems and other simple questions to answer on next dive at the depths you would already be diving while keeping track of depths and the time it takes to answer the questions.

When back at surface you'll likely have worse handwriting and slower times answering simple questions than you would expect... (And both individually and as a diver of 30 years you may have a moderate tolerance, but the above test helps quantify even though getting narked also varries situationally due to a variety of factors like warm water vs cold water).