Nitrogen narcosis

[airliner]

Hello everyone,
Last weekend I experienced something and I need your comments.
My instructor decided to make a deepdive to 50 meters. We all prepared our gear made the necessary controls and after the briefing we started to dive.
The visibility was poor, water temperature (salt water) was 14-15 degrees, because of the high density of planktons after 20 meters the light was poor too. While we were going down suddenly I felt something bad, sort of fright, poor vision, fear of passing away, and watching my instructor going away from me (she was below me during the dive) and I immediately stopped and give the problem sign with my torch while doing that I tried yell to take my instructors attention, there I thought to start ascending however my brain ordered me to stay where I am when I checked my dive computer it was showing a depth of 54,2 meters... she came by me and we started slowly to ascend together and everything got better. It is obvious that it was nitrogen narcosis however I reaaly don't understand why it came so suddenly,and felt like I was loosing my conciousness? what made me stop in such a bad condition? maybe we were too fast while descending? Because its the season start and it was only the 3rd dive of this summer?

Thank you all for your comments.

 

[ajduplessis]

You are correct in your diagnosis of nitrogen narcosis. There are various reasons contributing to the effects and why it happen that sudden for you. Maybe you could give us more information on what gas you dived with, and what exposure protection you used?

Post-Dive Analysis: If you have a DC that tracks your dive, it would be a good idea to analyse the data to get a better understanding of water temp at depth, ascend rate and nitrogen loads at various points in the dive, and compare it to your feelings during the dive.

Your observation on quick ascend could have added, however I believe that the low visibility, and high nitrogen loads was main culprits in you feeling of loss consciousness “falling into darkness”. The dive completed successfully and you have gained valuable knowledge on deep diving. Document what you experienced and manage your future dives based on these notes.

 

[Tortuga68]

Cold water, low viz, limited workup (3rd dive of the season), descent rate and descent position (head down) can all increase the onset & effects of narcosis

Since you were already below your taget depth and your instructor was below you, you did the right thing to stop, and since you weren't happy, thumb the dive - well done

Can you share some more details? Your previous deep experience, the previous two dives of the season, your descent rate (which you might be able to get from your computer), your position during the descent, the dive plan and why your instructor exceeded the target depth?

Not looking to criticise you or your instructor, just to give some feedback based on more data

 

[The Chairman]

NetDoc's second rule of diving: You can call a dive at any time and for any reason: NO QUESTIONS ASKED!

You did great! Narcosis is a sneaky bastard, and doesn't always warn us as to how he's gonna play with your mind. In other words, he just doesn't play fair. You were narced at 25 meters, but you probably didn't feel it. See how sneaky he is? Then at some point, you were affected enough to finally notice, but then you were way deep. Some people experience fear and paranoia while others experience peace and nirvana. It doesn't matter because your problem solving faculties are screwed up either way. That's the real killer side of narcosis.

The deeper you go, the more you have to plan and the more you have to train.

 

[airliner]

You are correct in your diagnosis of nitrogen narcosis. There are various reasons contributing to the effects and why it happen that sudden for you. Maybe you could give us more information on what gas you dived with, and what exposure protection you used?

Post-Dive Analysis: If you have a DC that tracks your dive, it would be a good idea to analyse the data to get a better understanding of water temp at depth, ascend rate and nitrogen loads at various points in the dive, and compare it to your feelings during the dive.

Your observation on quick ascend could have added, however I believe that the low visibility, and high nitrogen loads was main culprits in you feeling of loss consciousness “falling into darkness”. The dive completed successfully and you have gained valuable knowledge on deep diving. Document what you experienced and manage your future dives based on these notes.

We used air. 5mm semi-dry diving suit. I believe the descent was fast and we were head down....as you said I gained valuable knowledge. I'll give the dc info later, I have to first download the date to pc. Thank you for your answer.

 

[airliner]

Cold water, low viz, limited workup (3rd dive of the season), descent rate and descent position (head down) can all increase the onset & effects of narcosis

Since you were already below your taget depth and your instructor was below you, you did the right thing to stop, and since you weren't happy, thumb the dive - well done

Can you share some more details? Your previous deep experience, the previous two dives of the season, your descent rate (which you might be able to get from your computer), your position during the descent, the dive plan and why your instructor exceeded the target depth?

Not looking to criticise you or your instructor, just to give some feedback based on more data

well my previous deep dive was to 52 meters in aegean sea where the sunlight was still available and the visibility was perfect, and there were no signs of narcosis at all, however that was a ten days of a diving trip and ı was well adapted both physically and mentally to diving..after three or four days of continious dives(2 dives per day), so I believe my body was well adapted to +levels of nitrogen and so the effects of nitrogen was decreased. The previous dives were at 9 th of may this year where the sea temperature was 11-12 degrees and the visibility was again poor, however the depth was 36,5 meters at first dive and 27,6 meters for the second dive, no problems faced. I don't know why my instructor exceeded the target depth. I'll give the dc details on coming days after ı complete the dive profile downloads..My dc is new so I have to discover it a little bit more . Thank you for your answer.

 

[_Remko_]

We used air. 5mm semi-dry diving suit. I believe the descent was fast and we were head down....as you said I gained valuable knowledge. I'll give the dc info later, I have to first download the date to pc. Thank you for your answer.

I would seriously consider getting a more responsible instructor. He went beyond the planned depth and going to 54 meters on air?

What exactly was the goal of the dive? Was it a depth chase or was there actually something worth seeing/risking your life for?

 

[_Remko_]

I don't know why my instructor exceeded the target depth.

Because he was narced? Sounds like a good question to ask him why, if he can't give a solid reason he probably was narced.

 

[Tortuga68]

We already have enough deep air bashing threads, let's not make this another one, thanks

well my previous deep dive was to 52 meters in aegean sea where the sunlight was still available and the visibility was perfect, and there were no signs of narcosis at all, however that was a ten days of a diving trip and ı was well adapted both physically and mentally to diving..after three or four days of continious dives(2 dives per day), so I believe my body was well adapted to +levels of nitrogen and so the effects of nitrogen was decreased. The previous dives were at 9 th of may this year where the sea temperature was 11-12 degrees and the visibility was again poor, however the depth was 36,5 meters at first dive and 27,6 meters for the second dive, no problems faced. I don't know why my instructor exceeded the target depth. I'll give the dc details on coming days after ı complete the dive profile downloads..My dc is new so I have to discover it a little bit more . Thank you for your answer.

Thanks for the additional detail. Sounds like a slower desecent in vertical trim may have reduced the issue, although there's a fair difference between 37m and 55m, especially in the conditions described, and additional workups to 45m within a shorter timeframe could also have helped

 

[airliner]

NetDoc's second rule of diving: You can call a dive at any time and for any reason: NO QUESTIONS ASKED!

You did great! Narcosis is a sneaky bastard, and doesn't always warn us as to how he's gonna play with your mind. In other words, he just doesn't play fair. You were narced at 25 meters, but you probably didn't feel it. See how sneaky he is? Then at some point, you were affected enough to finally notice, but then you were way deep. Some people experience fear and paranoia while others experience peace and nirvana. It doesn't matter because your problem solving faculties are screwed up either way. That's the real killer side of narcosis.

The deeper you go, the more you have to plan and the more you have to train.

Thanks for saying that, because I am sure that if I've had continued to descend I would loose my conscious, thats for sure. I'll continue training for deep dives, at least I'll first adapt my self to diving more often and then step by step increase the depth..

Thank you for the answer.