Scared of Nitrogen Narcosis

[dkktsunami]

As Saudi-Diver mentioned, building experience slowly is a very good idea, maybe in ten foot increments. Don't get comfortable with 60' then decide to go to 130'. Also, when you do expand your comfort zone, do so with a diver that is experienced with depth and who knows your concern. Scuba diving is best learned with baby steps.

 

[Jim Lapenta]

Fortunately you are going to the Keys where just about all the ops I know of are very safety conscious. As an OW diver you will be hard pressed to find one reputable op that will take you somewhere with a hard bottom below 60 ft. Most of the reefs will require you to bring a shovel if you want to get deeper than 40 or so! Any deeper dives will require an AOW cert. Unlike other places like Cozumel and the Caymans where it seems the DM's/Guides look for ways to put people at risk by not following suggested limits. These places prey on the ignorance of new and poorly trained divers to say "oh c'mon. You will be fine at 100, 120, even 130, and in a cave or cavern or on a wall with the bottom at 2000 no less), we do it all the time"!

I'm glad to hear that you will say something if uncomfortable and unsure. This saves lives. Do not trust anyone to lead you somewhere your gut tells you is not a good idea to go. The use of a middle finger is entirely appropriate in those circumstances.

 

[PatW]

Well there are plenty of great dives at Key Largo that don't get below 30'. At those depths, I don't see you having any problem.

I have been down to about 112 feet. I have not noticed any narcosis. But I tend to get really cautious and watch my gauges and air closely at depths below 80 feet. So that concentration would probably hold the effects at bay.

My wife, who has been down deeper says that she had a friend who just started to wander off at 110' for another look at the other side of a wreck even though she was getting low on bottom time.

I understand that narcosis hits people at below 90'. The effects vary widely person to person (like alcohol and other intoxicating drugs). The effects of narcosis on judgement impairment probably depends on the self discipline and the amount judgement one has to begin with. A rash and impulsive person suffering from nitrogen narcosis would be in a fix.

I have been on quite a few dives where other divers have gone down to 100' plus. I have yet to hear of any problems with narcosis. Narcosis is something to be aware of at depth. But with most people, it is manageable. If you start to notice some impairment, you can always ascend.

 

[PatW]

Jeni,

I found the following comments on nitrogen narcosis with increasing depth or pressure. The first pair of numbers is bars (a unit of pressure), the second is depth in meters, and the third is depth in feet. If you do shallpw dives in Key Largo, 30' or less, you will probably not notice anything. It says one can have mild impairment or euphoria at depths up to 100'. Deeper than 100', one can get into problems with poor decisions and so on. The really severe effects occur at depths beyond recreational diving limits. I did not see a source for this information but the language looks as if it was taken from a reference source.

At 60' and less, you should be fine.

Pat

Comments
1–2 0–10 0-33 Unnoticeable small symptoms, or no symptoms at all.
2–4 10–30 33–100 Mild impairment of performance of unpracticed tasks.
Mildly impaired reasoning.
Mild euphoriaEuphoria (emotion)
Euphoria is medically recognized as a mental/emotional state defined as a profound sense of well-being. Technically, euphoria is an affect, but the term is often colloquially used to define emotion as an intense state of transcendent happiness combined with an overwhelming sense of contentment. The...
possible.
4–6 30–50 100–165 Delayed response to visual and auditory stimuli.
Reasoning and immediate memory affected more than motor coordination.
Calculation errors and wrong choices.
Idea fixation.
Over-confidence and sense of well-being.
Laughter and loquacity (in chambers) which may be overcome by self control.
Anxiety (common in cold murky water).
6–8 50–70 165–230 Sleepiness, impaired judgment, confusion.
Hallucinations.
Severe delay in response to signals, instructions and other stimuli.
Occasional dizziness.
Uncontrolled laughter, hysteriaHysteria
Hysteria, in its colloquial use, describes a state of mind, one of unmanageable fear or emotional excesses. The fear is often caused by multiple events in one's past that involved some sort of severe conflict; the fear can be centered on a body part or most commonly on an imagined problem with that...
(in chamber).
Terror in some.
8–10 70–90 230–300 Poor concentration and mental confusion.
Stupefaction with some decrease in dexterity and judgment.
Loss of memory, increased excitability.
10+ 90+ 300+ Hallucinations.
Increased intensity of vision and hearing.
Sense of impending blackout, euphoria, dizziness, manicMania
Mania, the presence of which is a criterion for certain psychiatric diagnoses, is a state of abnormally elevated or irritable mood, arousal, and/ or energy levels...
or depressive states, a sense of levitationLevitation
Levitation is the process by which an object is suspended by a physical force against gravity, in a stable position without solid physical contact...
, disorganization of the sense of time, changes in facial appearance.
Unconsciousness. Death.

 

[Garth]

wow, that last post was depressing. Glad to hear we now can avoid most of the last symptoms with Trimix. I'll be sure to look out for that when I take my course.

 

[DiveNav]

So you think it's rare to have the effects above 60 feet?...

How many Martini can you drink before you are getting drunk?

Check this out

 

[SoccerJeni]

How many Martini can you drink before you are getting drunk?

Check this out

Shoot! I can't get that link to work. I copied and pasted it in the address too and couldn't get it it open. I'll try it again later.

 

[deepdvr1]

Narcosis will hit everyone differently. Educate yourself on the effects, and dive within your limits. I also recommend taking a nitrox course. Nitrox will reduce the amount of nitrogen that is on gassed during your dive and reduce the effects of narcosis.

 

[Cave Diver]

I also recommend taking a nitrox course. Nitrox will reduce the amount of nitrogen that is on gassed during your dive and reduce the effects of narcosis.

The validity of that in practice has been debated back and forth for a long time. Oxygen also has narcotic properties that are just as great as Nitrogen.

Nitrox is great for reducing tissue saturation, but for real reduction in narcosis you would need to look into a heliox course or similar that replaces a gas with something less narcotic.

 

[Coral-Reefer]

I had never conciously felt the effects of nitrogen narcosis until I dove Devil's Throat one time. I have dove it before and it is an almost identical dive every time so it serves as a pretty good standard to judge the effects. Of course, there are numerous other variables that effect the situation like everything that happened the 12-24 or so hours prior to the dive, but anyway....

Once as I was coming out of the tunnel at 129', I felt "different". I wasn't exactly dizzy, but felt dizzy without the spinning... hard to describe. It was not pleasant or elating. All I knew was it was not "normal" and recognized that I needed to ascend, consciously and slowly. I did not panic but did feel a bit anxious. My dive buddy was still in the tunnel but I located the divemaster (you have to have a divemaster in the marine park in Cozumel) started a slow ascent and did not feel "normal" again until 91'.

Cave Diver and Cleavitt, along with others, have it exactly right. Do not fear it but understand and respect it.

Oh, and as far as your deep apprehension, get the advanced and enjoy; my wife, who is claustrophobic, does not like water too much (lake diving? yuck!), swore, during her first dive trip, she would not go below 25 or 30' and definitely not to 100', now is the first in the water, loves the first dive because it is deeper, loves the cave swim throughs and is always the cheerful one when we get back on the boat! However, she still won't be caught in the lake with me!

Enjoy your diving, you have found one of the hidden gems of enjoyment on our planet.