Deep diving advice that goes against conventional thought?

[100days-a-year]

One would hope that rescuer never becomes needed,I was taught self rescue via skill,training,gear,redundancy and if deeper than I feel comfortable working on air He mixes.

 

[MXGratefulDiver]

Dan, there are some realities we have to deal with here. You're referring to a "deep air" instructor selling certs to OW1 grads.

First reality ... you can't sell helium to people at that level ... the risk of serious injury to a new diver breathing helium due to their newly-formed buoyancy "skills" outweighs the risks presented by narcosis.

Second reality ... these divers are not likely to be going deeper than 100 feet, which is the recommended depth limit for the follow-on class, whether you're calling it OW2, AOW, ASD, or whatever your agency du jour happens to sell the class as.

Third reality ... even a Deep Diver specialty class only gets you to 130 feet ... which generally requires more dives and better buoyancy skills. Narcosis is one of the topics that's pretty thoroughly covered in that class, and one of the objectives of the class is to allow divers to experience it under controlled circumstances. I've used that objective rather successfully to help my students understand why chasing depth is perhaps not as good of an idea as they thought it was ... which will help them make better dive planning choices once the class is over.

I really, truly, dislike your analogy for a bunch of reasons ... it's unrealistic, it doesn't accurately reflect reasonable analogies to the realities of training recreational level divers, you're comparing an illegal activity to one that's perfectly legal and acceptable at both the social and industrial levels, and you're conflating two completely separate types of diving ... recreational "deep" diving and dives below recreational limits. There are a whole bunch of considerations that need to go into the techniques and training methodology offered to these two disparate audiences, and "to helium or not to helium" only pertains to one of them.

You need to separate the audiences, and decide whether you're talking about recreational diving or deep dives that exceed recreational limits ... those are entirely different conversations.

... and regardless of what anybody is selling, it's still the responsibility of the buyer to make an informed decision to buy. That's the message I want to impart on my divers from Day One of OW class ...

Only YOU are responsible for your safety. There are a lot of choices involved, in equipment, training, planning, and execution. Choose wisely ... and don't rely on someone else to make your choices for you. That's called "Trust Me" diving ... and it can put you in places you won't be able to get yourself out of.

... Bob (Grateful Diver)

 

[danvolker]

Some distinctions

I am talking about deep air.....to me that is deeper than 130 feet. Also, I am not aiming this at 99% of deep air instruction, even though I am not fond of it...Most of my anology is really about the deep records, whether on air or with mix.

More to the point....

Diving IS like a Drug.

Many of my cycling friends have "cycling" as a drug...they will ride 50 to 100 miles in a day, this will give them an "Endorphine" high, and it is every bit as great to feel this, as it is to get the feeling of doing a long line of coke.....We have been on 30 mph group rides with 60 other cyclists, in the middle of a 62 mile ride, and Sandra will start yelling " Im Flying....I'm Flying...." , and sometimes break into an aria ( opera)....

Diving is similar..like with cycling, many people feel much more relaxed, and de-stressed after diving or cycling.
If you have had a rough week at work, diving is an awesome way to forget the world, and live only in the moment...and experience this alternate universe....it is almost an LSD trip for some. I have no doubt, that some sginificant dopamine shift occur in the brain for many people during a great dive...maybe not as strong with the illicit drugs...at least not for most people...

And then there is deep air....the "ultimate high"....In the mid 90's, we would miss a week for bad weather, and then say we were "jonesing" for our deep air fix......And 250 to 280 on air, is better than coke, better than booze....and there is no hangover after it.... This IS a great high.
The deep diving lifestyle, of the deep air diver, is building a certain dependence and weekly stress relief, on the deep dive they look forward to...and the changes in brain chemistry it brings....

So a guy that take normal divers, and gets them to start doing 200 foot or so deep air dives, on a frequent basis....is he sort of like a "bartender" for the experience he is serving up....for the stress relief and the intense euphoric period of each dive the instructor "teaches" you how to have...and then enjoys with you....??

I think there are responsible bar tenders, that don't want their customers crazy and sloppy drunk...and I think there are bartenders that don't give a rat's a*s about their sloppy drunk customer leaving the bar with car keys in hand.

I think there are responsible deep air instructors that really make an effort....but these still have much in common with a really good bartender.
And I have known some bartenders that are very good and moral people, so this is no affront to a dive instructor that gets compared to one.

 

[DCBC]

1. Yes
2. Yes, it is all impairment and task-loading regardless of the activity
3. Yes, (not at lunch)
4. Yes, of course.

Ok, so you seem to be fine with diving while impaired. Then like me, I assume you feel that as long as the extent of a person's impairment doesn't prevent a reasonable degree of physical/mental performance (and the diver accepts the consequences of his/her actions), no harm is done.

There is always a trade off, an acceptance of impairment and the risk/reward. Above 100' EAN is fine. Why? Statistics, very little goes wrong above 100' with experienced divers. Truly, if HE was cheap I would dive below 60'.

So you believe that statistics should be the guide? Statistics say that a married man lives longer than a single man, so you encourage your children to marry anyone as soon as possible? You don't drink, or smoke because statistically your chance of disease increases? You don't drive a car because statistically your safer to take the bus or walk? Always exercise a minimum of 1 hour a day because an active lifestyle is more healthy?

I suggest that you take risks every day and don't always side on the side of statistical probability. If this is ok for you, why do you criticize others for doing exactly the same thing?

The question is, if you needed help immediately, life and death, what level of impairment would you want your rescuer to have? And when you get that answer, why should you dive any different?

I'd first want them trained in rescue techniques initially. Are you aware that Instructors from some certification agencies are prohibited from teaching OW divers sub-surface rescue at all? Some agencies don't even require people to know how to swim before they're certified! Are all divers you have ever dove with rescue trained?

I don't dive with a Buddy when I dive Deep-air unless I'm aware of my Buddy's in-water capabilities at that depth. In my opinion, certification standards are insufficient to depend upon these as an indicator of competence. There are Instructors that I've dove with that I wouldn't give an OW card to, so don't get me going on in-water performance...

 

[jadairiii]

One would hope that rescuer never becomes needed,I was taught self rescue via skill,training,gear,redundancy and if deeper than I feel comfortable working on air He mixes.

Not the answer to the question, but a great punt, you should play for the NFL.

But it is an unfair question (for deep air divers) because I already know the answer that everyone would say, while hanging by a thread, they would want the rescuer as clear headed as possible!

---------- Post added March 14th, 2014 at 04:30 PM ----------

.....
I'd first want them trained in rescue techniques initially. .....

That is a given, so just answer the question, it simple, Impaired or not impaired.

 

[DCBC]

That is a given, so just answer the question, it simple, Impaired or not impaired.

I would want the rescuer's to be unimpaired, or only impaired to a degree in-which his physical and mental performance did not detract from his ability to perform a competent rescue.

I'd give the same answer if the question was if I was a passenger in your car. It's for you to have one beer and drive, as long as your impairment didn't effect your reasonable ability to safely do so.

 

[Akimbo]

…That is a given, so just answer the question, it simple, Impaired or not impaired.

It isn’t that simple. Everyone is impaired to varying degrees, especially in high-stress life threatening situations. Concentration focuses under stress, partly as a coping mechanism. That is great sometimes, unless you neglect to notice an even greater danger on your periphery.

I have friends who can’t seem to exercise optimum judgment without morning coffee, thus they are impaired. I am impaired without a good night of sleep, am hungry, thirsty, or have a full bladder! Impaired is not binary.

---------- Post added March 14th, 2014 at 02:17 PM ----------


Back to the original question:

The diving described in the OP is certainly high risk but isn’t without precedent. I agree that some of their theories are not supported by current hyperbaric thinking but the fact remains that they are pulling this off, if you accept the assertions.

Most of the precedents for this kind of short-duration deep-air diving are from third-world divers harvesting high-value products like black coral and first-world divers that pre-date wide-spread availability of decompression tables. Both classes of divers ended up badly crippled from repeated DCS injuries, but rarely killed themselves diving.

In this case, it appears that these divers have enough knowledge to keep from bending the crap out of themselves and are able to avoid being severely incapacitated by Narcosis (manage and/or acclimatize themselves). They also manage to carry sufficient air to make the round-trip, though probably with less margin than most divers are comfortable with.

There is probably more to it than a few good-old-boys in a dare-fest. The novelty would ware off after a few dives. I also doubt very seriously that they discovered these limits after a few beers celebrating their OW cards… mostly since they aren’t dead yet. More likely they slowly worked up to greater depths after a considerable number of exposures… probably chasing larger fish. I have little doubt they scared themselves a few times along the way and that keeps them from going even deeper.

These divers seem to have discovered their limits, extreme as they might be. Perhaps that is the important lesson for every diver.

I don’t know these guys, but have seen the evolution. Most of them were after oilfield diving contracts instead of fish, but the process is the same.

 

[kr2y5]

Akimbo, thanks for your very informative response, I appreciate it. A few comments inline...

I have no idea where you got that.

You seemed to be referring to divers using Trimix at 130' as being "gullible", that would imply it is wrong to do so, hence my question... but perhaps I misunderstood your intention. As you stated, individual tolerance is highly variable. As a new diver, I would definitely want to do a number of similar Trimix and air dives to 130' before I can state with any degree of confidence that my limits lie beyond that, and since our local conditions are usually cold and gloomy, I won't be surprised to feel the difference even at shallow depths.

Trimix at 130' is an unnecessary expense

What I do take issue with is stating the 130' is the safe limit for the entire diving population

Unnecessary is a highly subjective term... as you said, impairment is individual. I vividly remember a dive when I had to unglue my wife from a wreck at 110' and heading for the sand, she clearly shouldn't be diving air to 130'. Also, as you pointed out, impairment is hard to measure accurately... I'd add that some people can afford Trimix more than others, and some are more risk averse than others... so as you said above, it would be very odd if placing the limit at 130' represented the right balance of risk vs. cost for everyone.

Countless studies have shown that the vast majority of healthy divers do not experience significant impairment at that depth.

I just wonder, how vast is the majority... this term could be misleading, since for example I wouldn't want to dive profiles that give me 2% rate of DCS, even though at 98%, arguably the "vast" (even "overwhelming") majority of such dives would be uneventful. Also, I wonder how this is measured given that...

Divers who report narcosis symptoms and demonstrate poor work performance universally show improvement on successive dives. Part of that is probably due to coping mechanisms,

The real question is: What depth does IGN become a significant impairment to diver safety, not where it can be measured.

...given that, as you say, testing impairment is so hard, in large part because performance on routine tasks improves even on subsequent dives, whereas it is allegedly the creative, higher-level thinking processes that primarily suffer from narcosis, and those are the very capabilities that we will want to critically rely upon in an emergency situation. With this said, I'm wondering what comes first: impairment to safety, or detectable symptoms? Is it the same for every diver? From what I've read here and elsewhere, it wasn't obvious to me so far.

Given human variability and acclimatization, it makes more sense for an individual to slowly work your way deeper and evaluate IGN for yourself.

I can believe this is true for some very experience divers... I'm just wondering, over how many dives this sort of awareness begins to materialize, and at what point I can trust my subjective self-assessment. I haven't got a clue after 100 dives... how long will I have to practice and how do I remain safe in between?

 

[Akimbo]

…You seemed to be referring to divers using Trimix at 130' as being "gullible", that would imply it is wrong to do so, hence my question... but perhaps I misunderstood your intention…

Not quite. I am referring to people who declare that Nitrox and Air at 130' is unsafe for the entire diving community. Even if those individuals have unusually low tolerance to Narcosis, I don’t see how they can ignore the vast body of evidence that it is safe for a great many divers. What is gullible is accepting the doctrine without analyzing the education they must have been exposed to in order to get a Trimix card.

By that standard, Cousteau and his entire diving team were on the edge of disaster for decades. How do they explain the very low fatality rate in the world’s diving population before Trimix was popularized in the early 1990s? How do they explain the 130' recreational limit recommended by very liability-conscious training agencies?

I have no problem with people who make an informed decision based on their experience working up to whatever depth they choose to switch to Trimix. I do have a problem with unsupportable proclamations that fly in the face of personal experience and large bodies of evidence.

…Unnecessary is a highly subjective term... as you said, impairment is individual. I vividly remember a dive when I had to unglue my wife from a wreck at 110' and heading for the sand, she clearly shouldn't be diving air to 130'…

Maybe, maybe not. Anxiety and elevated blood CO2 go hand and hand as does Narcosis. Divers can easily exhibit poor judgment on common recreational Trimix, even without elevated blood CO2 when anxious. People do stupid things all the time on the surface. Not all stupid things done underwater can accurately be blamed on Narcosis.

To reach your conclusion with reasonable certainty requires more than one exposure — ideally slowly increasing the depth on different dives until a reliable and somewhat predictable threshold is determined. Did she agree with your assessment after surfacing from that dive? Maybe she felt and was fine since 130' isn’t unreasonable.

…I just wonder, how vast is the majority... this term could be misleading, since for example I wouldn't want to dive profiles that give me 2% rate of DCS, even though at 98%, arguably the "vast" (even "overwhelming") majority of such dives would be uneventful…

True but if you slowly work your way deeper on repeated dives to discover your individual narcosis threshold, the answer is irrelevant. The “numbers” that are reliable are based on young, healthy, and physically fit males (excluding alcohol issues) in the world’s Navies. They are the only organizations with enough money to perform significant human testing and are free enough from legal liability concerns to pull it off. How well this applies to you and your bride is an unknown.

Does it really matter if you and your bride are in the top 20% or 0.00002% sensitivity range? What matters is drawing accurate conclusions and acting accordingly.

…I can believe this is true for some very experience divers... I'm just wondering, over how many dives this sort of awareness begins to materialize, and at what point I can trust my subjective self-assessment. I haven't got a clue after 100 dives... how long will I have to practice and how do I remain safe in between?

Simple, you practice and remain safe by progressing deeper at a rate that you are comfortable with. I get the impression that you think that Narcosis sets in suddenly and completely at “X” depth and you are unaware at “X”-10'. That’s not how it works. Repeated exposures at a moderate depth like 80' will allow you to become comfortable enough to feel confident that you can assess yourself. A conservative approach would be to increase by 10' and repeat. There’s no reason to be in a big hurry.

You might find this post useful: http://www.scubaboard.com/forums/ad...9-nitrogen-narcosis-whats-up.html#post6964055

If so, you might enjoy the entire thread.

---------- Post added March 14th, 2014 at 09:20 PM ----------

This also applies to my assessment of dives made entierely for the purpose of setting depth records.

[rant]Just for the record: [/rant]
My personal opinion is 500' surface supplied is nuts and untethered is beyond silly. Not that it can’t be done, just that you don’t have enough bottom time to accomplish anything useful and the probability of serious injury and death is too high to justify not serving a purpose.

If the purpose is some kind of bragging rights, put that in perspective. Saturation divers have been working far deeper than that 24/7 for 40 years. Is boasting that you grabbed a handful of mud at 500' and can still walk and hold your bodily fluids going to improve your life? Your choice.

That depth is the job of saturation divers, ROVs, and one-atmosphere suits. You can’t pack enough gas even with a rebreather to cover reasonable contingencies and not nearly enough is known about bounce dive physiology for decompression tables to be reliable. Compound that with not having a chamber on the surface to treat DCS and you may as well play Russian Roulette.

 

[DCBC]

...I'm just wondering, over how many dives this sort of awareness begins to materialize, and at what point I can trust my subjective self-assessment. I haven't got a clue after 100 dives... how long will I have to practice and how do I remain safe in between?

Few divers have the unlimited ability to dive in a dry/wet chamber and be monitored by hyperbaric professionals. Confirming what a diver thinks they're experiencing and what is actually the case can be difficult in OW.

The definition of Deep-air is a matter for interpretation. It use to be thought that Deep-air was Air used in excess of 130 FSW (the recreational maximum recommended depth). It appears now to have a different meaning; depending on who you ask.

I understand that the learning/adaptation process of Deep-air is prolonged and many may find it much easier to obtain a Trimix card. This is especially true when people today have a choice where more than one gas may be available.

This is not always the case; as I've been many places in the World that didn't have HeO2 or Trimix readily available (Tobago is but one example). If you want to dive, you use Air. If it's a wreck in 150 FSW you can either elect to stay on the boat (with your Trimix card) or dive on Air (I'm diving).

I'm not opposed to divers using mix on every dive over 100 FSW (if that's their choice). I've been endangered by divers on air as a result of Narcosis. In one particular case, a number of Instructors from Habitat (5 of us) were diving solo, together on Air (the only gas available on the island in 1978). It was a wreck penetration dive. I exited the wreck and started my ascent. I came to the aid of two divers; one was severely narced and the other frozen (situated about 20 ft above the wreck in 180 FSW). The narced diver went OOA who I assisted. A few seconds later, the 2nd diver went OOA (I've documented this dive in the 'lesson's learned' section). Obviously they were not diving within their safe diving envelope, nor were they close to being prepared for such a dive (The Mari Bahn, Bonaire, http://www.youtube.com/watch?v=vYKR97iW-yA).

I don't teach Deep-air; nor do I encourage others to dive Deep-air. My personal choice of mixture is guided by the complexity of the dive, depth, conditions and availability of gas. Generally speaking, I prefer mix over 150 FSW in an overhead environment and past 200 FSW in OW (although I've used mix in shallower water). Again it depends upon the complexity of the dive and the variables.

If people want to dive Trimix in 20 FSW, that's fine with me. If they want to attempt to set a world record on Air, they're free to do so. I've realized that I have enough challenges and responsibilities looking after my own diving (and at times my students) without worrying about what others choose to do of which I have no control.

The level of risk a person is comfortable with varies from person-to-person. Many divers don't dive in overhead environments because the risk is too high for them. I have no problem with their choices, unless they feel they can impose their choices on me.

---------- Post added March 15th, 2014 at 06:50 AM ----------

I was thinking of this thread and felt that a little humor was appropriate (courtesy of Road Kill T-Shirts, a SB sponsor):

I'm not saying you're stupid. I'm just saying you've got bad luck when it comes to thinking.

I like you. You remind me of when I was young and stupid.

I'm not here to judge, just to point-out all the mistakes you're making.

Of course your opinion matters. Just not to me.

I did not mean to offend you. That was just a bonus.

It's ok if you don't agree with me. I can't force you to be right.

I'm not saying I'm Batman. I'm just saying that nobody has ever seen me and Batman in the same room together.

Grammer: The difference between feeling your nuts and feeling you're nuts.