200' on air for 5 min bottom time?

[PfcAJ]

Since you asked...

The thing that stops people from dying of alcohol poisoning is the fact that people pass out (and therefor stop drinking) after drinking a bunch of booze and that most people vomit when they've drank a volume of alcohol that could kill them. Drinking enough to surpress the drive to vomit is really tough (but doable). Most people that DO vomit don't aspirate, either. The ones that do sometimes die, sure, but the above reasons and why most of humanity doesn't die from alcohol poisoning.

In regards to the analogy between a drunk person making a judgement on if they are impaired (or not), think of how many people say "I'm fine to drive, I've only had x drinks", even if x is a pretty high number. My personal favorite is "I'm a better driver when I've had a few drinks. I'm much more careful." That sounds right up there with doing the little self checks deep air guys love to talk about to make sure they're 'okay'.

I've said this in other deep air threads, but virtually EVERY death below 100' has had an END greater than 100'. There just aren't nearly the same volume of deaths for low-END deep dives, and the only reason to dive deep on air is $$. That's it. People don't want to pay for the training, the gear, or the gas.

I am NOT suggesting that you need trimix for every dive outside of a swimming pool. That's silly. I am saying that adaption to narcosis doesn't fly for novel situations, "self checks" are not good enough, and playing it conservatively is the only responsible option if you want to visit things that are deep.

 

[Slamfire]

I've said this in other deep air threads, but virtually EVERY death below 100' has had an END greater than 100'. There just aren't nearly the same volume of deaths for low-END deep dives, and the only reason to dive deep on air is $$. That's it. People don't want to pay for the training, the gear, or the gas.

I am NOT suggesting that you need trimix for every dive outside of a swimming pool. That's silly. I am saying that adaption to narcosis doesn't fly for novel situations, "self checks" are not good enough, and playing it conservatively is the only responsible option if you want to visit things that are deep.

I think that in principle most agree that narcosis is real and is dangerous. Helium alleviates narcosis, thus helium is good. The disagreement seems to be in the magnitude of the limits. I don't like putting words into anybody else's mouth, but it sounds like you advocate a universal mandatory limit of max END 100'. GUE training stds certainly do so.

This is one place where I just plain disagree. Correlation is not causation. Doesn't it stand to reason that the vast majority of people that dive in between 100' and 130' do so without any helium at all? That makes it logical to expect that most deaths will be from people that have no helium in their tanks. I've done it, but I personally just find it very wasteful to use 25/25 or 21/35 for a dive to max 130'.

Furthermore, adhering to a mandatory max END of 100' is no magic immortality elixir. I know that is not what you are saying, but some inductive reasoning folks might interpret your writings as if all you have to do is keep it within END 100' and you're golden. You and I know that coming back healthy from a dive involves much more than just plain using the std gas for the prescribed depth.

 

[PfcAJ]

I think a ~100' limit is a pretty good number with a very good track record, and its not absurdly conservative. For more complex dives (like caves, as is my forte'), I back it off even more. I also wouldn't refrain from doing a dive slightly past 100' on air/nitrox, either. But once you start getting past about 120', I raise a serious eyebrow, esp at things like 'tolerance', 'adaptation', and 'self checks'.

Agreed, correlation doesn't mean causation. 100% correct there. BUT, I struggle to think of any deaths with a sub 100' END when diving below 100'. There might be a handful. Its pretty compelling, but a low END is not a magic carpet, either.

The guys in that video, I think we can all agree, are an accident waiting to happen, and its more than just END that could do them in.

 

[oldschoolto]

This thread is getting old...... I think i'll go over to the blood clot thread and tell everyone that I'm diving with deep vain blood clots...

Jim....

 

[lamont]

I think that in principle most agree that narcosis is real and is dangerous. Helium alleviates narcosis, thus helium is good. The disagreement seems to be in the magnitude of the limits. I don't like putting words into anybody else's mouth, but it sounds like you advocate a universal mandatory limit of max END 100'. GUE training stds certainly do so.

My CCR instructor (and the manufacturer of the units) also recommended an END of no more than 80 feet (basing END calcs off of not including O2 as being narcotic like GUE does).

And around here for the past 10 years I think all the deaths have been using air/nitrox. I don't think there's been a single trimix fatality or severe near-miss like kirby's (I might just have not had my caffeine yet this AM, but I'm not thinking of any...).

Not to say there haven't been any near-misses on trimix, but they've been CO2 incidents were everyone manage to get to the surface unhurt or people sucking down O2 on the boat, or type 1 hits that resolved in the chamber... Once case of type 2 inner ear DCS on a 330-foot dive that I'm aware of that happened on the boat.

 

[DCBC]

... I don't think there's been a single trimix fatality or severe near-miss like kirby's

There have been. For example, the summer before last a Trimix Diver perished on the Andrea Doria (a wreck I originally did in the summer of 1974 on Air). As I know you can appreciate, it takes much more than an ideal gas mixture to make a safe dive...

---------- Post added June 3rd, 2013 at 01:48 PM ----------

... virtually EVERY death below 100' has had an END greater than 100'.

This statement just isn't true.

... "self checks" are not good enough, and playing it conservatively is the only responsible option if you want to visit things that are deep.

There's nothing the matter with conservative, but obviously you just don't have the experience that your "over 5000 hours" would normally indicate. The world is a big place that is mostly water. If you travel the world and dive in it, you will notice that Helium just isn't available everywhere. With the exception of CCR (where a few small bottles of Helium will go a long way) it's not something a Diver can carry with him. Prudent people can learn to dive Air at depths greater than 100 FSW safely..

As I said previously: Who are you to say how deep a diver can dive to safely on Air?

 

[PfcAJ]

If its not true, it should be easy to give me a list of a bunch of deaths. Deeper than 100', END less than 100'.

If I could make my profile just say 'infinity' I would, but I can't. And I've been a few places, and you *can* get helium, it just costs more dollhairs than what people want to pay. "Can't" and "won't" aren't the same.

Safe and incident free are not the same thing. Diving deep while doped up on nitrogen isn't safe. Sorry man. And who am I to say? Refer to line 1 of this post. Surely you will deliver, right?

 

[DCBC]

If its not true, it should be easy to give me a list of a bunch of deaths. Deeper than 100', END less than 100'.... Sorry man. and who am I to say? Refer to line 1 of this post. Surely you will deliver, right?

You're the one that made such a rash and inclusive statement. Now you want me to prove you wrong? Another ridiculous comment.

I've already mentioned the Doria death on Trimix. If there is one death with an END above 100 FSW, you're statement's incorrect. You said "virtually EVERY death below 100' has had an END greater than 100'." That's just not true and you're aware of this.

Regardless of the END, if the Diver has little common sense, he's an accident waiting to happen...

If I could make my profile just say 'infinity' I would, but I can't. And I've been a few places, and you *can* get helium, it just costs more dollhairs than what people want to pay. "Can't" and "won't" aren't the same.

The fact remains that Helium isn't available everywhere (although arrangements can be made in many areas for a price). It's usually a prerequisite to use reasonable parameters to form the basis of a conversation. What's affordable, is therefore interpreted to mean 'what is reasonable for the average person.' At $150 a dive (or more) for the cost of mix only, added to the standard dive costs, it can be prohibitive for most people going on a diving holiday. I've known people that get into CCR for this reason. Like others have stated, it's wasteful to do a some dives on mix, if it can be safely done on air.

Safe and incident free are not the same thing. Diving deep while doped up on nitrogen isn't safe.

Perhaps this is your opinion because you have been "doped-up on nitrogen" and made an unsafe dive. You can speak for yourself, but you can't speak for anyone else. This does not give you cause to make unsubstantiated statements that are directed towards the diving practices of others. IGN affects everyone differently and at different times.

If you personally can't accurately predict when to stop drinking alcohol; perhaps you shouldn't drink at all. If you can't safely ascertain if you are safe past 50 FSW on Air, it's best that you don't dive deeper than that. IGN is affecting you at 50 FSW and if you don't understand that, maybe you should consider using mix on all your dives, or pick a different hobby...

 

[HIGHwing]

I've known people that get into CCR for this reason.

I have Microsoft Excel and it didn't take a complex spreadsheet for me to figure that one out for myself.

 

[Slamfire]

My CCR instructor (and the manufacturer of the units) also recommended an END of no more than 80 feet (basing END calcs off of not including O2 as being narcotic like GUE does).

Helium use in a Meg or Pathfinder is hardly wasteful. On CCR you really have no excuse. Heck, you might as well just bring it up to 50 END and still be nowhere near the wastefulness of OC.

Congratulations. What did you get, Meg or Pathfinder? I've been thinking about getting a Meg, but then rEvo's also look very attractive... Eventually I have to calm down these forbidden desires by elevating a prayer to Irvine and asking him to reassert rule number 5 within my diving. But I have to confess that it is getting harder and harder and peer pressure is intense. Last time (Cinco de Mayo) I was diving in your neck of the woods I was the only one on OC. Everybody else was on Megs. They were threatening with throwing me overboard along with the grapple so that the CCR guys could follow my bubbles into the wreck... :depressed: