Deep Air - Here we go again....

[Scott L]

This thread kills me. Some suggest lower END's for safety while some others argue for the ability to decide for themselves. The current situation in scuba allows for complete flexibility so everyone is free to choose their own route. Clearly the thread's main purpose is to provoke GUE followers so why fuss when they respond?

 

[ucfdiver]

This thread kills me. Some suggest lower END's for safety. Some others argue for the ability to decide for themselves. The current situation in scuba allows for complete flexibility so everyone is free to choose their own route. Clearly the thread's main purpose is to provoke GUE followers so why fuss when they respond?

No, currently it allows for the people who FIRST dive the sites to choose. There are some of us who never get to dive a site because someone else decided to save $100 and choose for us. How do you think the recent eagles nest fatality with a nearly 200ft END helps land owner relations? I'll give you a hint, the site was closed not too long ago.

Could you please provide the quote and reference for this? It does not coincide with my materials, which match your other points precisely.

GUE Cave Manual, Page 46

Neither the NSS-CDS or NACD has training for Helium, so they limit full cave to either 100 or 130ft, I think this is different in different versions of the manual. To be honest, I sold my workbook because I don't have a need for it anymore, so I can't reference either of those texts.

 

[MXGratefulDiver]

Bob, when I get home tonight, I'll remove the dir stuff from my avatar and sig line, and take it out of my profile. I'll add in my naui cert since its more palatable.

What would be more palatable would be to stop making some of the commentary you've been making lately. I've enjoyed an awful lot of your posts, and believe you to be a knowledgeable diver. But last week you aimed some crap at someone I've dived with ... and happen to KNOW isn't the incompetent diver you claimed him to be.

That sort of thing leaves an impression ... one you probably would prefer not to have.

But, to answer your question, no, I do not have much experience outside of cave diving. However, I do have the ability to assess accidents and make correlations. This doesn't have anything to do with gue.

... in the environment you dive in. But this thread wasn't specifically about cave diving. I'm very new to cave diving ... but I can already tell you it's a very different environment, with its own set of rules. Accidents in a cave happen for very different reasons than accidents in open ocean.

Before passing judgment on someone else's fitness to their point of view, you need to be able to relate to their experiences. A broader exposure to different diving conditions tend to change the way you look at things.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

This thread kills me. Some suggest lower END's for safety while some others argue for the ability to decide for themselves. The current situation in scuba allows for complete flexibility so everyone is free to choose their own route. Clearly the thread's main purpose is to provoke GUE followers so why fuss when they respond?

Why would you think so? This isn't in the DIR forum. It's not in the cave forum either.

Step back and look at it from a broader perspective ... if there was an intent to provoke, I think it would've been posted in a forum specific to a more targeted type of diver.

... Bob (Grateful Diver)

 

[ucfdiver]

But last week you aimed some crap at someone I've dived with ... and happen to KNOW isn't the incompetent diver you claimed him to be.

Great, you know him! Why don't you (in public, like you're doing to AJ) ask him to stop using age to "cut down" divers he's having a discussion with?

 

[boulderjohn]

GUE Cave Manual, Page 46

Neither the NSS-CDS or NACD has training for Helium, so they limit full cave to either 100 or 130ft, I think this is different in different versions of the manual. To be honest, I sold my workbook because I don't have a need for it anymore, so I can't reference either of those texts.

You've mixed your references.

You talked about the research done by the cave community on the most common causes of fatalities, and you said that #4 was ENDs >100-130 feet. The reference you cite is from another source on the topic of ENDs and not from the research you referenced.

I do have the NSS-CDS book that lists those items, and I do have Scheck Exley's book that cites the original research. Neither one mentions ENDs >100-130 feet. As I said before, fatlaity cause #4 is diving beyond the limitations of your training. The NSS-CDS book does not mention ENDs in in its explanation in the list of fatalities for the general diving community (which is where the list you cite is mentioned) at all.

In the section of fatalities restricted to the trained cave diving community, exceeding the depths of your training is actually the number one cause for fatalities. (That's because trained cave divers are likely to use guidelines, etc.) In describing that, it adds information based on the fact that the studies you referenced were done before helium was commonly used:

Today, with the use of breathing gases other than air, one must consider the Maximum Operating Depth (MOD) of the gas they are using. Equivalent Nitrogen Depth (END) should not exceed 130 feet / 40 meters.

 

[Scott L]

Why would you think so? This isn't in the DIR forum. It's not in the cave forum either.

Step back and look at it from a broader perspective ... if there was an intent to provoke, I think it would've been posted in a forum specific to a more targeted type of diver.

... Bob (Grateful Diver)

I simply cannot fathom a training agency not suggesting that END's be limited for recreational technical divers. If yourself and the OP were given the responsibility of running a major training agency what would be your standands? Just friendly conversation...

 

[hg frogman]

Because the reality is : it depends.

Using Helium reduces the narcosis but adds its own set of dangers (there are a few of these, but this is not the topic of this thread).

Sure for most open water dives deeper than 50 to 60 meters, Trimix is better than Air for adequately qualified and trained divers ! (With OxTox being a very good reason, IMO even better than narcosis, for not going too deep on Air, BTW)

Sure cave diving or wreck penetration are heavy workload for the brain and have their own set of rules or recommandations to keep narcosis out of the equation as much as possible !

No one contests this so far.

But you have no right to claim that using Trimix is intrinsically safer than using Air for open water dives within the limits set for Air by most training agencies for adequately qualified and trained divers, ie 50 to 60 meters (165 to 200 feet).

Because there is no evidence supporting this.

That may even be the opposite. I am more afraid of DCS than of narcosis for the open water dives I am talking about, and it's easier to do a mistake leading to DCS (eg unproper ascent or screwed-up runtime) with Trimix than with Air. And I am not even talking about the number of experiments available for dive tables with Air, compared with the Trimix. Or with the extra burden (stages etc) going with the Trimix. Or with the overconfidence that can go with the knowledge that there will be no narcosis with the Trimix.

So please stop generalizing without any proof.

 

[ucfdiver]

You've mixed your references.

You talked about the research done by the cave community on the most common causes of fatalities, and you said that #4 was ENDs >100-130 feet. The reference you cite is from another source on the topic of ENDs and not from the research you referenced.

I do have the NSS-CDS book that lists those items, and I do have Scheck Exley's book that cites the original research. Neither one mentions ENDs >100-130 feet. As I said before, fatlaity cause #4 is diving beyond the limitations of your training. The NSS-CDS book does not mention ENDs in in its explanation in the list of fatalities for the general diving community (which is where the list you cite is mentioned) at all.

In the section of fatalities restricted to the trained cave diving community, exceeding the depths of your training is actually the number one cause for fatalities. (That's because trained cave divers are likely to use guidelines, etc.) In describing that, it adds information based on the fact that the studies you referenced were done before helium was commonly used:

It mentions depth, instead of END, because at the time Sheck wrote that book, END was irrelevant (no helium tables or training). Neither the nss-cds or the nacd has revisited this issue in depth since that time. If you look at the requirements to dive Alachua or Waynes World, they're pretty clear that you have to be certified to dive gases appropriate for depths. Since we're all certified for nitrox/air, I seriously doubt that's what's implied by the nss-cds when they state that rule. The nss-cds cave diving articles and opinions might be a better source for more modern info...

 

[boulderjohn]

It mentions depth, instead of END, because at the time Sheck wrote that book, END was irrelevant (no helium tables or training). Neither the nss-cds or the nacd has revisited this issue in depth since that time. If you look at the requirements to dive Alachua or Waynes World, they're pretty clear that you have to be certified to dive gases appropriate for depths. Since we're all certified for nitrox/air, I seriously doubt that's what's implied by the nss-cds when they state that rule. The nss-cds cave diving articles and opinions might be a better source for more modern info...

Sure, it could be, but that is not why I posted.

Maybe I am being overly picky, but whenever I see people make specific claims that a specific source says a specific thing, then I believe the reference needs to be accurate. If you know my history, I am forever correcting people on the many, many times they misstate statistics from DAN.

You specifically said that a specific source said something it did not actually say. You said they state that exceeding equivalent nitrogen depth is a key factor in fatalities, and they do not say that. Perhaps one might infer that exceeding those depths was a factor, but that is not in the source. I know that if someone were to quote me and misstate what I had said, I would not be pleased.

If other sources have something else to say on the matter, then you can cite those sources and quote them accurately.