Narcosis??

[Waterpolo]

Still fairly new to diving, so I read about and talk to as many divers as poosible in order to learn about the various experiances, good or bad, everyone has, in hopes of retaining some of the knowledge for my own benefit.

There is still one question I have, or better yet, one scenerio I am always wondering about and that is.. how can you tell that you have had any level of narcosis during or after a dive? I understand what factors bring on this condition, but I am curious as to some of your personal experiances with this, and how you knew or what you think were the causes leading to the condition.

I ask this because I attempt to dive by the book on every dive I make, paying very close attention to my tables and my ascent time and safety stops, but some times I will experiance a light headedness feeling during and for a short time after, the dive.

I would appreciate anyone sharing there experiance or knowledge on this topic so that I get a better understanding on what exactly might be happening when I dive. Thanks.

 

[H2Andy]

think of narcosis as diminished mental ability, sometimes coupled with euphoria or feelings of dread

you are affected pretty much as soon as you are under pressure, but you don't notice it until the effects are large enough (usually around 100 feet) to get your attention

narcosis symptoms usually resolve themselves when you ascend 10 to 20 feet from the "offending" depth; they usually are difficulty in concentrating and task-performance, impaired judgment, impaired decision-making ability, and sometimes dread or giddiness.

i don't think that feeling light-headed after a dive is a narcosis issue. it may be a CO2 issue that is depriving your brain of O2 and causing the light-headed feeling

i look forward to what others have to say

 

[The Chad]

Usally anyone who dives to 100' is impaired to some degree, you might think your not but you are. Attempt to spell your name using handsigns and one can see the delay.

I've seen guys on deco dives reach for their 100% O2 at 70' thinking it was their 50/50 nitrox. It just happens and to varying degrees in ppl.

 

[Dave Zimmerly]

On some dives at around 90'-100" I start to hear classical music. It hits everyone differently, some will deny it, but it happens. Just start to ascend slowly and do your safety stops.

Dave (aka "Squirt")

 

[loosebits]

Lightheadedness is not a usual symptom of narcosis. Narcosis only exists at depth and has no lingering effects once you ascend.

I have no idea what is causing your lightheadedness but I would recommend calling DAN and asking them. They are always very helpful.

Edit: Wow, 3 other replies while I was typing this.

 

[MSilvia]

I think H2Andy's description is spot on. Diminished mental capacity is usually the first and most significant sign of narcosis I notice.

One time, I knew I was narced because I just checked my guage 3 times and I don't have a clue what it said. On another occasion, I aborted a dive when I couldn't figure out how to read the NDL countdown on a computer I'd used over 50 times previously. On yet another occasion, I surfaced from a dive near the recreational limit with about a dozen pictures, but I only remembered having taken two or three.

I'm often euphoric when diving, so that's a much harder sign for me to identify. I've learned that I'm pretty suceptable to narcosis after about 110fsw though, so I'll usually be extra vigilant or use trimix for those dives now.

 

[lazyturtle]

I find narcosis manifests itself as a mild time distortion for me. When I find myself checking my bottom time every few seconds I know I'm narced. So for me it manifests as a mild paranoia that makes me check things far more often than nessicary (not really a bad thing..)
Different people have different thresholds for depth. I have a friend who feels too narced to dive at 90 feet, whereas I find myself starting to feel it on dives deeper than 110 or so. Personally it's never affected me strongly enough to make me end a dive, but I can see how it could.
Lightheadness could be caused by your sinuses adjusting slowly to the change of pressure, I've had many divers complain of this in the past.

 

[Scuba-Jay]

An Instructor friend of mine in Key Largo likes to tell of a diver he was supervising on a wreck dive who proceeded to hand off his primary air source to an Eel which was lying on the timber beneath him. The student told my friend later that he was under the impression that the Eel was in an OOA situation and was only trying to provide assistance.....

 

[sharkattack]

Trimix/ Triox will clear that up

 

[String]

Trimix/ Triox will clear that up

and cause near immediate bankruptcy.