Deep Air Diving - thoughts

[cave_diver]

In my experience, you will get “narked” at any depth – it is just a matter of time. Yes, I feel that the body adjusts to deep diving and I feel the narcosis less and less after many dives.

However, I would be very careful diving deep on air. You can have a bad day, and the narcosis kicks in when you don’t expect it. If you have a task load (i.e. if you are deep in a wreck or 3.000 feet back in a cave), you will have a serious problem.

I enjoy diving and I would not risk my live anymore to be able to tell anybody I did a deep air dive. I was down well below any safety limit on air when I was young, and it was stupid. Get Trimix certified if you want to dive deep. At least you will remember your dive.

 

[RiverRat]

Yep I agree. I question divers that say "I wasn't narced at all" on a deep dive. I think some divers just don't want to admit it. I've been on dives, not all that deep, and when you have to work hard, like in some current, the old CO2 hits can really kick in the narc feeling. And as we know CO2 is a bad gas itself. I won't go too deep on air. The next step for me is TDI Advanced Wreck and Basic Trimix. If I want to go into a wreck below a 100 feet I'll spend the extra $ for some helium. I won't be doing those dives all the time due to cost but when I do those dives it'll be nice to have done it properly.

 

[String]

Im quite happy to admit i get narc'd and my tolerance varies wildly. Some days im noticeably suffering at 30m, other days im feeling it less even though im at 50.
If im planning something deep and start to get that buzzing of narcosis earlier than i'd like i abort. Simple as that. If im happy to continue i do.

Yes there is more risk, yes there is more impairment but its another one of those cost:benefit analysis that only the individual can do and make their own mind up how far they're going to push it.
Trimix i cant afford the £80 or so per dive so a lot of my diving is a choice between seeing the wreck and accepting some risks or not diving at all.

 

[divindoc]

"Deep Air Diving - Thoughts"

The very title is oxymoronic.

 

[Tomeck]

54 would make sense thinking of the pp1.4 for oxygen. Not sure i like the narcosis on that though (although i freely admit i dive to that depth on air all the time as i cant afford the 10x cost per dive that trimix would mean)

The ascent with trimix is more complicated than with air. The trimix is not always an advantage, because of the ascent and it is much more expensive. If I dive up to 50 meters, I prefer air.

 

[jhoey]

<snark>

I don't have a problem with drink driving - it's all about knowing your own limits and working up to it gradually.

If you're planning on going out with your drinking buddies and getting really wasted one night, you have to spend the previous few evenings preparing for the Big Drink. Here's how you do it:

Over a couple of weeks, get progressively more drunk so you can build your alcohol tolerance. And do so at progressively greater distances from home; just make sure you take the same route back home every time so that you can build the necessary muscle memory to compensate for slowness of reaction times and lack of higher cognitive functions. This is called Progressive Penetration.

Once you've done that, you should be able to drive all the way back home no problem, even in a semi-conscious stupor. I've done it dozens of times, and while I've put a few minor dings and scratches in my car I've never had a major crash, so that proves it can't be all that dangerous.

Let's face it: the people who insist on driving home sober are just weekend warriors who can't be bothered to put in the time and effort to be able to do it drunk. I strongly believe that if you aren't capable of driving under the influence, you certainly shouldn't be on the roads in the first place.

BUT - after you've logged enough miles under the influence and you've developed the muscle memory to deal with the journey home while drunk, it might be worth investing in training to be able to drive sober. But that's a highly advanced form of driving that shouldn't be taken lightly - sober drivers are capable of driving faster, which is of course far more dangerous.

Another factor militating in favor of drink driving is that taxis are so expensive. And in some areas, especially rural areas, you simply can't find taxis at all. Given the choice between driving drunk and wasting money on expensive taxis, I'll drive drunk and accept the minor increase in risk that it involves.

</snark>

 

[jhoey]

The ascent with trimix is more complicated than with air.

No. It. Isn't.

It simply requires enough buoyancy skill to hold your deco stops at the appropriate depths.

Okay, yes - if you rocket to the surface on Trimix, you're more likely to get bent than if you do so on air. But if your buoyancy skills are so poor that ballistic ascents are a concern, then you really shouldn't be deco diving in the first place.

 

[String]

But if your buoyancy skills are so poor that ballistic ascents are a concern, then you really shouldn't be deco diving in the first place.

Or in fact diving at all without close supervision.

 

[Thalassamania]

<snark> ... </snark>

Put down the glass and step away from the Kool-aide. We will get you help. Help is on the way. Stay calm. Everything is going to be alright.

 

[peterbj7]

You know, there are a lot of arguments and entrenched positions on this largely based on semantics. The technical meaning of "narked" means that according to objective measurements your blood chemistry is temporarily altered, and that is undeniably true for all divers regardless of experience level.

But that isn't what most people mean by "narked". They mean "your behaviour and awareness is significantly altered", and hence also your safety.

Although the physiology doesn't vary much from person to person (though it does vary to an extent, based partly on age and related issues and BMI, but largely by your state of hydration at the moment), the subjective psychological state varies a great deal, largely according to experience level. People accustomed to entering the realms of physiological narcosis exhibit far more minor symptoms than people new to the game.

It really annoys me when pedants base their case on physiological aspects, which most divers are unaware of at the time, and wilfully ignore the considerable psychological differences which are what people are actually affected by. In any meaningful sense, experienced divers do get narced much less than inexperienced ones.

I have no doubt that said pedants will condemn what I have just said as irresponsible and wrong. I am NOT in any way trying to encourage inexperienced divers to push depth on air because their symptoms are illusory, because they're not. But I am explaining the anomoly that many inexperienced divers notice, which is that divers experienced in deep air diving do it repeatedly without the accident/incident rate that might be expected if their abilities degraded in accordance with the objective physiological changes.

I suspect that if people were honest about their experience, those who most loudly condemn the practice of deep air diving are those with least experience of it. That probably applies to many topics here.