Deep diving advice that goes against conventional thought?

[DCBC]

Physics tells us that when we increase the partial pressure of N2 there will be in increase of impairment. You can’t get around that. What level of impairment varies but there is impairment. Oxygen and CO2 at depth also can affect the level of impairment. None of us are capable of operating outside the laws of physics, super heroes are just in the movies.

So what are you suggesting? Because every diver is somewhat impaired by IGN at 50 FSW that all divers use mix below 40 FSW? Does that sound reasonable to you? Are all the Agencies wrong by setting the recommended depth limitations for Air that they have?

Now, as a criminal defense attorney I have represented 100s of individuals for DUIs and watched 100’s of dash-cam/BAT videos of those people accused of DUI. I have seen clients with a .08 BAL totally fail roadside tests and other with .29 and above actually do pretty good on those tests. But those that had high BAL that performed adequately on the tests are still “drunk” (as those with the low BAL's) and I would not trust any of them in any task-loading situation. The proof of that is that they were all stopped because, although they “felt” good enough to drive, they could not. Ergo, why they were stopped, they could not perform the simplest task of keeping a car on the road.

I'm unaware of the laws in your jurisdiction. In Canada, driving over 80 mgs and Impaired Driving are separate charges. You can be convicted of impaired driving regardless of your blood alcohol content. A blood-alcohol content over 80 mgs is not proof in-itself of impared driving.

There are also thousands of cases where Police Officers have given breathalyzers where the reading was under 50 mgs and the driver showed no sign of being impaired. The driver is allowed to drive away. Is he impaired? Yes, but not to the degree where in the eyes of the law he has done anything wrong.

I find it difficult to compare IGN to alcohol intoxication. As I've mentioned, the mechanics of these are different. Driving with over 80 mgs is a crime; diving impaired by IGN (in 50 FSW or 500 FSW is not). They are not the same thing.

Let’s look at this from a different standpoint, going back to physics, we know there is impairment at 150, that cannot be disputed. I recently competed in a Sporting Clay tournament. At that tournament the range does not allow ANY impairment of the shooters. Personally I don’t know of any range that allows intoxicants. So ask yourself, if it is not safe to compete in a shooting tournament impaired, how is it “safe” to conduct a dive with much greater task loading at 150?

It would appear that you have not taken the time to read what I've already stated. "I do not drink and drive; as I do not believe that it's my right to endanger others. Nor do I encourage others to do so. On the other-hand, I do believe in individual rights (like choosing the diving equipment and gas the diver wants to use and conducting the dive as the diver sees fit)."

In your example, by being impaired, you would be endangering others. Something that I've already stated that I don't believe in.

Regarding your comment "...we know there is impairment at 150, that cannot be disputed." I agree with this, in-fact there is a level of impairment in 50 FSW.

Before we go further in this discussion:
Have you ever dove to 50 FSW or deeper on Air?
Do you feel that this is the same as drinking and driving?
Have you ever in your life had one glass of wine or beer at lunch and driven a motor vehicle?
If you did, would you consider yourself impaired at the time?

But the reality is, no one will change your mind that your not “good on air”, the real question is why are you so afraid of those of us that are trying to tell others that mix is better choice deep? Why does that bother your so? How does that affect you?

First of all I'm a mixed-gas instructor and have been for 40 years. I'm fully aware of its benefits and shortcomings. What I don't appreciate is that I'm "unsafe and reckless" on air in 150 FSW. This just isn't the case. I've been tested repeatedly by a number of Hyperbaric Physicians at various times and my physical and mental performance falls with the recommended guidelines at 200 FSW.

Now lets look at this question slightly differently. Is my performance improved by breathing mix beyond 150 FSW? Absolutely! Am I safe to dive Air at that depth? Absolutely!

Human performance can be a complicated area to assess. Is my safety compromised if I breath air at 150 FSW and take 3 seconds longer to complete a valve drill? No. Could my performance be improved on mix? Yes.

There are those that after they have a drink or two will run the 40 faster that I've ever been able to. Are they impaired? Yes, to some degree. Does this impairment affect their performance? I imagine it would. Is their level of performance acceptable? They beat a sober guy, so likely the answer is yes.

Is my performance impaired at 200 FSW on Air? Yes. Is my performance acceptable on Air at 200 FSW? Yes, as far as the Diving Medical Officer (Hyperbaric Physician) was concerned, it met the standards of performance set by the Navy. Could my performance be improved with mix? Yes.

I rest my case Councillor...

 

[Wookie]

My point....is that I think PfcAJ is RIGHT for the general issue...that goiung forward, with the massive population now interested in tech diving, and taking instruction in it....that rules need to be there for them, and this includes SAFE LIMITS for most of them--which equates to all of them for an agency rule.

I agree wholeheartedly with what you said in your entire statement, Dan, but I think this needs some fleshing out. While I agree with the sentiment, the slippery slope is that, like it has with all diving, creating limits and standards and inventing safer dive computers and bringing deep/mix/technical diving mainstream we run the risk creating the fallacy that tech diving (or may I call it "extreme diving" without getting in too much trouble) is safe, just like we have run into the OW diver who says "My hit was undeserved, I was within the limits of my computer". I do believe in undeserved hits, but the fallacy is that diving at any level is safe, where we all know it isn't as safe as sitting on the couch or laying in bed. I haven't been diving as long as you, but I probably have near as many dives. I didn't get to practice diving deep on air because Billy Deans hadn't brought helium mainstream yet. My stupid dive (we all have one, right) was to 186 feet on the eye of the needle in Saba on a single 80. I liked it. I went and got mix certified so I could do it "safely".

Agency rules aren't to keep divers safe. They are to keep the lawyers and insurance companies covered. Back in the day of LA County and YMCA, a c-card meant we could do a lot of things we can't do any more, because they have been deemed to be unsafe.... Now, we don't know where our limits are, nor do we know how to go find them.

 

[DaleC]

Excellent post Frank. And these days we are criticized as reckless for trying to find our own limits.

By quashing discussion of how to navigate the grey area we leave divers with two options: Dive as someone else tells them; seek their own path with no guidance.
People talk about reinventing the wheel when it comes to the outcome but I see this as reinventing the wheel in terms of the process ie. each individual needing to relearn how to learn.
What I have found is that the ability to learn is a transferable skill, that can be applied to any number of activities. The more you practice, the better you are.

Also, the downside to always believing you are diving within a safe envelope is that you can become complacent in the skill of self assessment. I'm diving H, I can't be narc'd, I'm diving best mix, I can't get bent, I'm diving in a team, I can't get overwhelmed... From what I've seen, complacency among skilled divers is as least as deadly at the tech level.

 

[John C. Ratliff]

Physics tells us that when we increase the partial pressure of N2 there will be in increase of impairment. You can’t get around that. What level of impairment varies but there is impairment. Oxygen and CO2 at depth also can affect the level of impairment. None of us are capable of operating outside the laws of physics, super heroes are just in the movies.

Now, as a criminal defense attorney I have represented 100s of individuals for DUIs and watched 100’s of dash-cam/BAT videos of those people accused of DUI. I have seen clients with a .08 BAL totally fail roadside tests and other with .29 and above actually do pretty good on those tests. But those that had high BAL that performed adequately on the tests are still “drunk” (as those with the low BAL's) and I would not trust any of them in any task-loading situation. The proof of that is that they were all stopped because, although they “felt” good enough to drive, they could not. Ergo, why they were stopped, they could not perform the simplest task of keeping a car on the road.

Let’s look at this from a different standpoint, going back to physics, we know there is impairment at 150, that cannot be disputed. I recently competed in a Sporting Clay tournament. At that tournament the range does not allow ANY impairment of the shooters. Personally I don’t know of any range that allows intoxicants. So ask yourself, if it is not safe to compete in a shooting tournament impaired, how is it “safe” to conduct a dive with much greater task loading at 150?

But the reality is, no one will change your mind that your not “good on air”, the real question is why are you so afraid of those of us that are trying to tell others that mix is better choice deep? Why does that bother your so? How does that affect you?

Just a note here, but as an attorney you should know the difference between physics and physiology. It is not physics which tells us about impairment by nitrogen at depth, but diving physiology (see Underwater Physiology, Edited by C.J. Lambertsen, Academic Press, New York, 1971, Part III, Physical Effects of Pressure and Gases, starting on page 85).

SeaRat

---------- Post added March 14th, 2014 at 09:59 AM ----------

For you DUI people, I am curious because I have never dived tri-mix, what is the cost to the diver of tri-mix? Do you fill single tanks with tri-mix?

Do you know that helium is a national asset of the USA, and that our supplies of it are limited. This is why I don't like filling balloons with helium--we don't have a whole bunch of it, and why waste it on balloons? Are we wasting helium on diving between 50 and 100 feet with tri-mix?

[h=3]Conservation advocates[/h]According to helium conservationists like Robert Coleman Richardson, the free market price of helium has contributed to "wasteful" usage (e.g. for helium balloons). Prices in the 2000s have been lowered by U.S. Congress' decision to sell off the country's large helium stockpile by 2015.^[89] According to Richardson, the current price needs to be multiplied by 20 to eliminate the excessive wasting of helium. In their book, the Future of helium as a natural resource (Routledge, 2012), Nuttall, Clarke & Glowacki (2012) also proposed to create an International Helium Agency (IHA) to build a sustainable market for this precious commodity.^[90]

SeaRat

 

[100days-a-year]

Blah,blah,blah blathery blather.20 years of internet hashing and you still have 8-10 guys on either side of the fence telling the other guys they are wrong,half of whom use verbiage they most assuredly would not use in person.One or two guys having civil and intelligent discourse occasionally.

If your personal abilities limit you sufficiently then use whatever you need to overcome them,not my business.By the same logic,if I don't feel your limitations constrict me do me the favor of reciprocating.

People dive air,get over it.AFAIK It is only in the US and Canada that HE is so readily available and cheap and the supposed upcoming helium shortage will have us all back to air or diving RBs which come with their own issues.They guys I personally know who have died have been equally distributed between OOA,deep air,current,cardiac,oxtox and various random factors.All were preventable,but at what point?Not diving certainly but giving up tobacco?not eating processed food or red meat?exercising more?not drinking the night prior?diving HE at Looe Key?surface supplied 02 deco?

At some point you might as well rub vagisil all over and lock yourself in a padded room,eating oatmeal,tofu and soymilk resigning your life to a series of boring uneventful days spent worrying if the radiation from the house wiring will cause you cancer...

 

[Akimbo]

I would be very sorry if someone was compelled to make a dramatic late-evening phone call with apologies based on a hypothetical discussion they witnessed on ScubaBoard, and without evidence that someone actually did the dive in question... speaking of gullible... …

What is dramatic or late-night about calling a friend a 7:00 PM (both on the Pacific coast)? A number of people wrote rather emphatically that they use Trimix at, and often shallower than 130'. I don’t understand how that is hypothetical?

…With this said, you now seem to be implying that there is something wrong diving Trimix below 130, which is more of a radical opinion than those stated earlier in this thread. Could you please elaborate on this, for the benefit of less experienced divers?

I have no idea where you got that. Trimix at 130' is an unnecessary expense — perhaps unless you have learned that you have an unusually low Narcosis threshold. Note that an unusually low Narcosis threshold is no more a personal criticism than sensitivity to bright sunlight. Countless studies have shown that the vast majority of healthy divers do not experience significant impairment at that depth.

Note that being underwater and in dive gear produces some measurable impairment in most new divers… which is generally racked up to distraction. The methodology of measuring impairment (beyond involuntary reflexes) is not as precise a science as one might think due to daily human variability, familiarity with the test environment, and life experience.

IGN (Inert Gas Narcosis) is especially problematic. Many of us who have performed extensive deep diving operations both as divers and supervisors have observed acclimatization. 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, but most commercial diving professionals believe that physiological acclimatization occurs as well.

The 130' depth was chosen as a recreational limit for a lot of reasons including gas consumption, decompression commitment, and IGN for the most sensitive and inexperienced people. It is not clear that many reports of IGN by new recreational divers are accurate since the symptoms they report are also common to elevated blood CO2.

Trimix does reduce gas density a small amount, because most recreational mixes use a small percentage of Helium. Lower density gas reduces the work necessary to ventilate the lung and is a positive factor in reducing CO2 levels in the blood. Many hyperbaric researchers believe that elevated CO2 and IGN symptoms are directly (biochemically) linked, but all the ones I am aware of believe CO2 is at minimum a significant contributing factor.

The real question is: What depth does IGN become a significant impairment to diver safety, not where it can be measured. With the exception of barotrauma, all diver maladies are very difficult to study and ultimately rely on human testing and field experience in order to verify and evolve theory. Reviewing studies conducted in several countries and over decades does not indicate that IGN is a significant performance inhibitor at or above 130'.

Millions of military, commercial, and recreational air and Nitrox dives have been safely executed for decades — approaching a century. Given human variability and acclimatization, it makes more sense for an individual to slowly work your way deeper and evaluate IGN for yourself. IGN is not an on/off switch. The symptoms gradually become more pronounced as pressure increases giving you plenty of opportunity to evaluate how it affects you and when changing mixes is appropriate.

What I do take issue with is stating the 130' is the safe limit for the entire diving population using air and Nitrox. That conclusion is simply not supported by the science or statistics.

Helium-Oxygen diving has been around before Cousteau and Gagnan developed the Aqualung. Therefore if IGN were remotely as debilitating as implied by many of the posts here, Helium would have been used long before a few armature divers in Florida starting promoting Trimix.

Contrary to common belief, Trimix is also nothing new. A lot of research was conducted in Europe starting in the 1950s, primarily as a means of reducing gas costs over HeO2. That work never evolved very far because the density of Trimix became too high at depths most researchers were targeting. However, it did verify that Helium does react differently in terms of tissue compartment saturation than Nitrogen. Much of that work lead to functional algorithms that enabled recreational Trimix diving today.

Further complicating the issue, IGN is also never a cause of death, only a potentially contributing factor. Granted, irrational performance is ultimately a/the leading cause of diver death. However the vast majority of fatalities occur much shallower than 100'.

 

[MXGratefulDiver]

I've known divers who show detectable symptoms of narcosis at depths much shallower than 100 feet. I set my personal limit at 120 feet ... at least in the cold, dark environment in which I normally dive. Below that I'd prefer some helium in my mix. I know people who routinely dive much deeper than I do without any helium at all ... but the one time I did a 150-foot dive on air I got so narc'd I could barely remember what to do.

It's important to set limits on yourself, based on personal experiences and preferences ... but it's silly to set those same limits on anyone other than yourself. We're not all the same, and you don't know where someone else needs to draw that line. Sure, there are safe diving practices that we should all generally follow ... but sometimes it's less about those than it is just a natural tendency to assume that if something doesn't work for you then it shouldn't work for anyone else either. But one size doesn't fit all in the real world.


[rant]
The drunk driver analogy breaks down at a certain point, because drunk drivers can and do kill innocent people. Narc'd divers only affect themselves, and potentially their dive buddy. If you're choosing to dive with someone knowing that they're using a mix you find unacceptable, you're not "innocent" ... you're complicit in that you chose to dive with them.

Calling someone else a "murderer" because they choose to dive or promote diving in a fashion that you don't find acceptable is beyond silly. It appears to be popular behavior among a certain segment of our internet population to use language like that, but it does nothing to engender reasonable conversation. It might be entertaining, if you're into train wrecks ... but nobody should take that sort of language seriously.

I know someone ... someone I truly like ... who used to routinely do deep air dives to well below 200 feet. He did this for a long time. And because he was such a likeable person ... you really won't meet a nicer guy ... a lot of people worried about him. Lots of us expressed our concern for the way he was diving, and he would tell us why he felt he was OK with it. We respected his decision, even though we disagreed with it. Eventually he did have an accident ... a bad one ... and although he survived, he's impaired for life and will never dive again. It would be easy to say "I told you so" ... and if it were someone I only knew through the internet it would be natural to consider him foolish. But knowing him personally is a different matter ... all I can say is I disagreed with the choices he made, but I respected his right to make them. He didn't do it out of ignorance. He knew exactly what the potential consequences were, and made his choice thinking he could handle it. Turns out he was wrong. Guess what ... we all are at some point, even among those who think they've got it all figured out. I've made plenty of mistakes while diving ... who am I to judge somebody else's?

One of the things I really like about scuba diving is the reliance on personal responsibility. You, and only you, are responsible for your safety. You make your choices and live (or not) with the consequences. I don't want to see that change ... not even at the cost of people getting injured or killed. Risks are the flip side of having the freedom to decide for yourself. I'm a big believer in informed choice ... share your views and information, talk about the downsides ... preferably without exaggeration or personal insults. And if somebody decides to dive in a way that's beyond what you're willing to risk, don't go diving with them. That's your right. But respect their right to make that choice ... just as you expect them to respect your right to make yours.

Sometimes we seem to not value those rights in our discussions. Perhaps because most of us are pretty informed, pretty experienced, and pretty passionate about the way we've chosen to dive. But in a lot of these conversations the level it degenerates to is counterproductive. Because with some people ... me among them ... there's an inherent aversion to being told what to do. And the level of discourse that inevitably creeps into the conversation causes the very people you're trying to reach to tune out what you're trying to tell them.

It's kinda like listening to something really interesting on a staticky radio station ... no matter how good the topic might be, eventually you just want to change the channel ...
[/rant]

... Bob (Grateful Diver)

 

[DCBC]

Well stated Bob.

 

[danvolker]

I've known divers who show detectable symptoms of narcosis at depths much shallower than 100 feet. I set my personal limit at 120 feet ... at least in the cold, dark environment in which I normally dive. Below that I'd prefer some helium in my mix. I know people who routinely dive much deeper than I do without any helium at all ... but the one time I did a 150-foot dive on air I got so narc'd I could barely remember what to do.

It's important to set limits on yourself, based on personal experiences and preferences ... but it's silly to set those same limits on anyone other than yourself. We're not all the same, and you don't know where someone else needs to draw that line. Sure, there are safe diving practices that we should all generally follow ... but sometimes it's less about those than it is just a natural tendency to assume that if something doesn't work for you then it shouldn't work for anyone else either. But one size doesn't fit all in the real world.


[rant]
The drunk driver analogy breaks down at a certain point, because drunk drivers can and do kill innocent people. Narc'd divers only affect themselves, and potentially their dive buddy. If you're choosing to dive with someone knowing that they're using a mix you find unacceptable, you're not "innocent" ... you're complicit in that you chose to dive with them.

Calling someone else a "murderer" because they choose to dive or promote diving in a fashion that you don't find acceptable is beyond silly. It appears to be popular behavior among a certain segment of our internet population to use language like that, but it does nothing to engender reasonable conversation. It might be entertaining, if you're into train wrecks ... but nobody should take that sort of language seriously.

I know someone ... someone I truly like ... who used to routinely do deep air dives to well below 200 feet. He did this for a long time. And because he was such a likeable person ... you really won't meet a nicer guy ... a lot of people worried about him. Lots of us expressed our concern for the way he was diving, and he would tell us why he felt he was OK with it. We respected his decision, even though we disagreed with it. Eventually he did have an accident ... a bad one ... and although he survived, he's impaired for life and will never dive again. It would be easy to say "I told you so" ... and if it were someone I only knew through the internet it would be natural to consider him foolish. But knowing him personally is a different matter ... all I can say is I disagreed with the choices he made, but I respected his right to make them. He didn't do it out of ignorance. He knew exactly what the potential consequences were, and made his choice thinking he could handle it. Turns out he was wrong. Guess what ... we all are at some point, even among those who think they've got it all figured out. I've made plenty of mistakes while diving ... who am I to judge somebody else's?

One of the things I really like about scuba diving is the reliance on personal responsibility. You, and only you, are responsible for your safety. You make your choices and live (or not) with the consequences. I don't want to see that change ... not even at the cost of people getting injured or killed. Risks are the flip side of having the freedom to decide for yourself. I'm a big believer in informed choice ... share your views and information, talk about the downsides ... preferably without exaggeration or personal insults. And if somebody decides to dive in a way that's beyond what you're willing to risk, don't go diving with them. That's your right. But respect their right to make that choice ... just as you expect them to respect your right to make yours.

Sometimes we seem to not value those rights in our discussions. Perhaps because most of us are pretty informed, pretty experienced, and pretty passionate about the way we've chosen to dive. But in a lot of these conversations the level it degenerates to is counterproductive. Because with some people ... me among them ... there's an inherent aversion to being told what to do. And the level of discourse that inevitably creeps into the conversation causes the very people you're trying to reach to tune out what you're trying to tell them.

It's kinda like listening to something really interesting on a staticky radio station ... no matter how good the topic might be, eventually you just want to change the channel ...
[/rant]

... Bob (Grateful Diver)

Well written post Bob, and even though I am at odds with you on this, I don't want to take away from how well you make your point with this....
But there is another side you ignore....
"Calling someone else a "murderer" because they choose to dive or promote diving in a fashion that you don't find acceptable is beyond silly. It appears to be popular behavior among a certain segment of our internet population to use language like that, but it does nothing to engender reasonable conversation. It might be entertaining, if you're into train wrecks ... but nobody should take that sort of language seriously."

Now I know you and a few others get annoyed when I use an analogy like this, but please bare with it once again.....
A drug dealer at a college is leading a lavish lifestyle, fancy cars, great parties, and lots of fun for people in this guy's circle....he gives away Qualudes to many in this group, and ultimately they feel this makes things more fun for them, and they begin buying with regularity.
Obviously I am comparing the drug dealer to the Instructor selling Deep Air certs to as many OW1 grads as they can find, with the lure of big adventures that are both affordable and requiring little in the way of delayed gratification. This is not exactly fair as a comparison, but in all fairness, neither the college kid selling qualudes, or the Deep air instructor, thinks that their actions will kill anyone.

And...Most deep air instructors are probably NOT going to get anyone killed, and any deaths will be of divers that had an informed understanding of the risks and realities of deep air. And then there is the deep air, and "Every Man for himself" crowd, and the "Lets break a Depth Record Crowd".... and if you add enough charisma to the personalities pedaling this, it can hook people in......Just like the parties and the Flash that go with the lifestyle of the Drug dealer.......and a great many deaths attest to this.
And where someone has been hooked in, that would not have taken this path, if not for the charisma, the romantic notions of Fame and Big Adventure, and the living on the edge glorified---without all this "pushing" this person in the dangerous direction, this person would never have taken this path, and ended up dead.
So when I connect these dots...as with certain of the people that pushed Sheck Exley into going for a deep diving record, I consider the person doing this "pushing" as someone that helped to cause a death....and in some of these cases, I would say that some involved were guilty of a crime....I can't actually call this crime murder...it does not fit the legal definition..not even negligent homicide....but I consider their behaviors as so dangerous, that they need to be seen by society as a pariah ( because of the likelihood of them doing this to many more people).

And this takes us back to drug dealers.....The ones at colleges I know of, don't expect their drugs will kill anyone. They think of the thrill, and the money they can make. Those of us that have seen them hook friends of ours into this dangerous path, to serious addiction ( I am not talking about just doing a line of coke 1x a week....I am talking about constant use of dangerous drugs) --those of us that have seen this can either decide it is not our responsibility ( which is the path outlined by Bob) , or they can take the path I have outlined, to decide that a friend of yours is being preyed on by a pusher ( works in the Deep Dive Records direction as well) , and that you have a responsibility to DO something to prevent the foreseeable death or serious consequences.

In diving, calling the police is not going to work....and even in the drug example, there would have been no good way to get the cops involved, without ruining the lives of too many good friends -- as collateral damage, when the drug pusher was to be "stung"....Sometimes it is not up to other people to fix things for you...sometimes you have to do things yourself...Sometimes, when you see a guy that is going to kill a friend of yours with their ideas--and you KNOW this will happen, sometimes you will need to see this person as someone intent on murder....and then YOU must take steps to prevent this.

 

[jadairiii]

Before we go further in this discussion:
Have you ever dove to 50 FSW or deeper on Air?
Do you feel that this is the same as drinking and driving?
Have you ever in your life had one glass of wine or beer at lunch and driven a motor vehicle?
If you did, would you consider yourself impaired at the time?
...

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

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'.

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?