Spare Air: some thoughts

[RJP]

According to you then, students and new divers should be told to never hold their breath but once they are comfortable diving, and have some experience under their weight belts, they can be told to "hold" their breath.

Thanks for clarifying.

:blinking:

OK idocsteve, since you're having some trouble reading my posts I want to determine if there's any sort visual or ocular problem causing the difficulty. Please cover your left eye, hang this thread on the wall, and tell me how far down you can see...

Of course that's not what I'm saying. In fact, I'm saying precisely the opposite. Just as we've never told our children "It's now OK to talk to strangers" neither do we ever specifically tell divers "It's now OK to hold your breath."

How's your understanding of Ray's point: Better? Worse? Same?

(click, click, click, click)

Let's cover the right eye this time. How about now...

On the other hand, just as our children's understanding of the underlying "never talk to strangers" concept evolves, so too diver's understanding of the underlying concept of what is meant by "never hold your breath" evolves - to the point that the can appropriately apply the concept to any and every situation in which they might find themselves.

OK, how about now: Better? Worse? Same?

(click, click, click, click)

This time, with both eyes. OK, how about now...

After they have an intellectual understanding of the rationale and implications, plus practical experience, divers (like children) mature to the point where they can think:

"OK, what the rule means is to always keep my airway open. Do not impede the escape of gas from my lungs by means of a physical barrier, such as closing my glottis. This is of particular importance upon ascending from depth to surface (or nearly any depth to any shallower depth) as gas in my lungs will expand per the physics I learned. Given the physiology I learned, it's clear why this would create an issue in a closed container such as my respiratory system. Given that the clear intent of the rule is 'to always ensure expanding gas has a means of egress' I now understand that there are times when it is appropriate to modulate my respiratory tidal volume via my diaphragm and related accessory muscles, as may be occasionally necessary or desired - but only while ensuring my glottis and other airway structures are open and gas can flow freely. I typically encounter such opportunities at a maintained depth or when making very minor changes in depth, such as drifting up 10" to rise over a coral head on a drift dive. However, as I get closer to the surface, where the pressure differential is much more significant for any given change in depth, it may best to keep the old adage 'never hold your breath' in mind, ensuring that I'm actually breathing out"

So, how's that?
Better? Worse? Same?
Hmmm...no issue related to visual acuity.

OK idocsteve I'm just gonna slide my slit lamp over here...Betty, can you hand me one those fluorescein strips. Hmmm...no signs of corneal trauma. OK, this is an applanation tonometer, and I;m gonna put a drop of 0.4% oxybuprocaine hydrochloride...there you go. Please hold still, and open your eyelid all the way. A little wider. All the way. A little more. Hmm. OK, I'm going to hold your eyelid open. And, there we go...don't move your eye. Stare straight ahead. Hmm. Looks fine.

Wonder what the problem is. If it's not the eye itself, maybe the problem lies elsewhere? Pituitary adenomata? No family history of Leber's. Ever diagnised with MS? No? Probably rules out optic neuritis. Cardiovascular disease? Anterior Ischemic Neuropathy unlikely. I'm stumped.

There's gotta be something behind idocsteve's eyes that is some how preventing him from seeing what I've clearly typed in my posts. Now what could it be? What is behind the eyes? There's gotta be something back there. Something the eyes connect to in order to allow idocsteve to interpret what he's seeing in a meaningful, intelligent manner? What could that be?

I'm just teasing...

 

[vshearer]

 

[idocsteve]

I'm a Christian idocsteve; you miss my point (Matthew 4:6-7).

And I'm an athiest idocsteve

Your psalms and biblical quotes mean nothing to me.

In fact, as far as I'm concerned, they mean nothing to anyone else either. They just don't know it.

 

[sdiver68]

I'm not seeing that at all. The diver who was the subject of the story had numerous options available to him, including his own octopus, and his buddy's octopus, as well as using problem solving skills which would have identified the cause (and solution) in a very short time.

Rather than choosing any of them he panicked and bolted for the surface.

I doubt he would have grabbed for a Spare Air even if it was readily accessible.

From the article:

http://seaduction.com/lessons-for-life/2010-01-diver-down-choking.html

"Consider using a completely redundant air source. This is the ultimate in self rescue and it works even with a first-stage failure or in an out-of-air situation. "

 

[Reg Braithwaite]

From the article:

Seaduction - Diver Down: Choking on It

"Consider using a completely redundant air source. This is the ultimate in self rescue and it works even with a first-stage failure or in an out-of-air situation. "

I'm sorry, but you are quoting the author's advice out of context. The story concerns a diver who had a fully functioning first stage, a fully-functioning octopus, and could also have breathed off his second stage without the comfort of a mouthpiece had he determined the cause of the problem. Here's my quote:

Perhaps the simplest solution would have been for Jake to simply switch to his own octopus which was affixed where it should have been and in perfect working order.

The mouthpiece separated from the second stage, the diver breathed in water, he panicked, and fled for the surface without ever determining what was going on.

While the advice you quote may or may not be good advice under various circumstances (note the word "consider," which is not same as the word "always"), I have to agree with those who say that when someone panics, there is no piece of gear that will save them.

FWIW, I think the only thing to help someone in this situation is an attentive buddy who can spot the issue and calm the diver down. Had someone offered him a long hose he might have taken it, calmed down, and sorted things out. And the author seems to agree:

Had Jake’s instructor been attentive to the divers on descent, as he should have been, he could have simply offered Jake his octopus while they sorted out the problem. Jake’s buddy was also nearby and he also had an octopus that was available.

None of this suggests a SpareAir or Pony is a bad idea. But I do think this incident is a poor example to use when advocating one.

 

[Blackwood]

FWIW, I think the only thing to help someone in this situation is an attentive buddy who can spot the issue and calm the diver down. Had someone offered him a long hose he might have taken it, calmed down, and sorted things out. And the author seems to agree:


None of this suggests a SpareAir or Pony is a bad idea. But I do think this incident is a poor example to use when advocating one.

[Anecdote warning]

Some good friends of mine were in the Red Sea a couple years back doing some wreck dives. I'm going to post an email (with names removed) regarding a similar incident that would seem to reinforce Reg's point.

On this dive I was slinging both an 80 stage and a 40 deco and had a scooter.

Were down at abt 165 and 10 mins in and Attentive Buddy gives the "u okay?"

I return the ok when all of a sudden I see concern in his eyes and he's donating his stage hose.

I'm confused but start taking it anyway when I inhale and breathe salt water. The mouthpiece on my not ****ty but not great rental gear had separated from the reg.

If you've never had that happen u really can't tell its gone. I was lucky to close my throat before too much [water] got in and popped Attentive Buddy's reg in.

So, in at least one case, an Attentive Buddy was able to see the problem before the could-be victim was even aware of it.

Personally, I'd dive with AB over SA any day of the week.

 

[BrotherBear]

I think you should have taken some of those "welcome to the world below the neck" electives they offered in optometry school...



There are two ways to "hold" your breath:

• Closing the glottis which seals the airway, trapping air in your lungs.
• Expanding your diaphragmatic, abdominal, and costal muscles to create a semi-rigid vessel which yet remains unclosed as the glottis is open

In both cases above your breathe is held: First in a sealed container. Second in a negative-pressure cavity. The second version would seem pretty safe to use in diving. .

I apologize for opening up this whole "holding your breath" discussion. It was a picayune complaint to a writer who almost assuredly knew not to hold his breath while ascending, as we all do, and was only incidentally germane to the topic at hand. And, like most of us, I hold my breath on every dive, just not while ascending. To the extent that there is disagreement on this, it is certainly semantic, rather than substantive. Again, my apologies.

As a n00b on this board I'm keeping my postings to a minimum for a while, but I've been following this thread with great interest. It's helping me learn some of the players very quickly...seperating the "thoughtful, I'm just trying to help" posters from the "I'm shrill and pendantic and just want to rationalize to win the argument" posters from the "unless otherwise specified people are idiots" posters...oh, wait a minute...that last one was me, never mind. Ahem, I digress...

As someone pointed out this is the basic scuba section of the forum and only a step above the raw newbie section. Being critical of a choice of words, for whatever reason that choice was made, is entirely appropriate. The common vernacular of "hold your breath" in the english speaking world is to fill the lungs with air and seal them off. Go ahead, right now, go pick someone at random and ask them to hold there breath for 30 seconds. I'll bet more than 9 out of 10 will suck up a deep breath, close their mouths, and close off their throats, they'll even puff up their cheeks for effect.
This is exactly what you would do at depth if you wanted to die of a ruptured lung while ascending during a scuba dive. Forget the hair-splitting definitions to forgive someone of an unintentional (probably) oversight, that is not constructive. What is important is the message that choice of words would convey to the uninitiated who will cruise this forum.

I was lucky enough to have a fantastic instructor who made it clear he would fail me if he EVER saw me with a regulator out of my mouth and no bubbles coming out (yes, hair-splitters, I know this assumes you have ANY air in your lungs). He was relentless on this topic and made sure I understood not only the rule but the reason and physics behind it. All this led to a cold chill running up my spine and a need to double and triple check the credentials of the poster who wrote the words "while holding your breath", I could not believe I was reading that here.
I'm not making any judgement about the poster, being a world wide forum it was probably a language goof-up...or maybe not. Just saying that certain things should probably be corrected quickly, obviously, and often lest a casual n00b reader get the wrong idea.

Anyway, thought I'd fianlly throw another .02 into this very entertaining thread...I'm hoping the helpful, the pendantic, the shrill, the rationalizers, the trolls, and those who just HAVE to have the last word in any argument keep this going ad infinitum, it's just too much fun

 

[MichiganScott]

And I'm an athiest idocsteve

Your psalms and biblical quotes mean nothing to me.

In fact, as far as I'm concerned, they mean nothing to anyone else either. They just don't know it.

Well I'n not an athiest, but that was funny

 

[Blackwood]

I'm not making any judgement about the poster, being a world wide forum it was probably a language goof-up...or maybe not. Just saying that certain things should probably be corrected quickly, obviously, and often lest a casual n00b reader get the wrong idea.

There are many misnomers and inaccuracies in dive education.

One of the great things about this forum is that those misnomers and inaccuracies are publicly corrected, such that the casual "n00b" reader can (finally) get the right idea.

We're often taught not to use our BC as an elevator and rather to ascend, descend and control buoyancy with our breathing. We're also told to never hold our breath while diving.

Well, if we can't hold our breath, then we can't ascend, descend or control buoyancy with our breathing.


If one defines "hold your breath" as "close your glottis" (which is what the big agencies mean even if they don't say it) then the rule is "don't vary depth with a closed glottis."

But that's harder to teach, and mainstream SCUBA education is all about what's easy to teach (to which the mere existence of a "get on your knees" hand signal attests).

 

[DCBC]

There are many misnomers and inaccuracies in dive education.

One of the great things about this forum is that those misnomers and inaccuracies are publicly corrected, such that the casual "n00b" reader can (finally) get the right idea.

We're often taught not to use our BC as an elevator and rather to ascend, descend and control buoyancy with our breathing. We're also told to never hold our breath while diving.

Well, if we can't hold our breath, then we can't ascend, descend or control buoyancy with our breathing.

Personally I don't believe this is a good idea for the new diver. Someone gave themselves an AGE in Ontario several years back by doing just this, too close to the surface. Using breathing should not be the way you control your buoyancy.

Shallow breathing leads to CO2 excess because of the lack of lung ventilation. Filling the lungs can may lead to air embolism. It's ok when your deep, but to your point, this is the Basic SCUBA thread. It's just bad practice for a new diver near the surface.