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I've seen many free flows in all kinds of conditions and all but 1 were 2nd stage.
Thanks. I've been wondering if my experiences were an outlier. Now I'm less concerned about that.
 
Open Circuit Cylinder Valve Feathering/Modulation Technique (often taught in advanced wreck penetration courses, it can be applied in my opinion to single tank open water diving as well):

With no buddy in sight-- and you have the option & ability to successfully make a calm effort in conserving as much free-flowing gas by the valve modulation/feathering breathing technique, what you gain is time --time for the Buddy to find you and gas share. If not, then perform a "modified" Controlled Emergency Swimming Ascent (CESA) while taking breaths as needed by the valve modulation technique as described below, and if possible with remaining gas & skilled enough to hold depth, do a safety stop. At the very least, the main objective is to safely reach the surface without suffering an AGE and with some tank pressure left to adequately inflate your BCD and Drysuit. You don't want an "out-of-the-frying-pan-into-the fire" SoCal worst case scenario of surfacing with an empty tank; getting tangled in kelp; inability to orally inflate the BCD because you're out-of-breath having just performed a conventional CESA; in a shrink-wrapped drysuit hampering mobility; and working hard treading water to maintain positive buoyancy in a typical prevailing 2' to 4' afternoon swell & wind chop --you had better at least be able to drop your weights!

To recap on an Uncontrolled/Unfixable Free-Flow:

Shut your tank valve down. When you need to take a breath, crack open the tank valve and shut it down again. Repeat as needed, switch to your back-up reg/octopus as well if the unregulated flow of gas from the malfunctioning primary reg is too much to "sip" from. Perform this tank valve "feathering/modulation" technique while doing a CESA (if your buddy is nowhere to be seen and you're essentially solo). . .With your left hand, slow your CESA rate via BCD/wing hose deflator dump button . . .with your right hand reach back, feather/modulate your tank valve and take breaths as needed.

The motivation after realizing that you can breath off a catastrophic non-fixable free-flowing 2nd stage reg, is to shut down the tank valve to stop further wasting/bleeding of precious breathing gas. If you have a pre-dive Rock BottomMinimum Gas Reserve Plan and you know how much pressure your tank has during all phases of the dive --if you lose or become separated from your Buddy for an instant-- then why would you let vital breathing gas bubble away because of an unfixable free-flow on an emergency surface ascent? Especially if you have the ability to reach and manipulate your tank valve on & off to take breaths while not panicking, maintaining buoyancy at depth, you have a moment on the chance that your buddy will find you again: And if not, then perform a nominal ascent with a safety stop while still modulating your tank valve as needed for breaths.

The actual incident that happened:
Cozumel 2006, my adjustment knob on the second stage blew-out resulting in a catastrophic nonfixable free-flow, on a single-tank dive in 6 meters of depth, during a weightbelt lead check. I actually could see the gauge pointer/indicator hand on the SPG sweeping from 200 through 150 bar literally in an instant before reaching back to shut-off the cylinder valve. Switched to my bungied back-up reg around my neck and then modulated/feathered the tank valve behind my head while doing a CESA.
 
Could the hose be kinked shut between breaths? Or would the risk of hose rupture be too great. What about removing the first stage from the tank and breathing straight off the valve? I have breathed off valves before that way so I know it can be done. But I have not tried it any deeper than an 8' swimming pool.
 
Open Circuit Cylinder Valve Feathering/Modulation Technique (often taught in advanced wreck penetration courses, it can be applied in my opinion to single tank open water diving as well):
IMNSHO, the average open water diver would benefit more from simply keeping calm, not panicking, and surfacing in a controlled manner while sipping from their reg (EDIT: or breathing from their buddy's secondary, of course) than from trying to manipulate their tank valve in a stressful situation (which a freeflow is to most of us, even if we've had it before and know that it's more of a nuisance than a crisis)
 
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In my opinion solo heroics and feathering are not the answer. The skill and the related standard are focused on a one-size-fits-all solution to a massive freeflow, which is

1) breathe
and
2) get to your buddy
3) end the dive

There is no standard and no training that I can remember for feathering a broken reg before getting to advanced training. Even then, it's usually something that is discussed in the context of a broken reg on a stage cylinder. For a broken back-gas reg, the protocol is usually

1) breathe
2) get the reg shut down
and
3) get to your buddy
4) end the dive

(or some variation thereof that makes the student feel suitably self sufficient).

Suggesting, as above that feathering a broken valve on a single tank and taking some kind of solo action to get to the surface without help is, in my opinion, poor advice.

Proper advice would be to make use of your back-up gear, which is ON YOUR BUDDY'S BACK.

The difference isn't academic. In many fatal accidents, the trigger is an OOA situation (which a massive free flow will become within a minute or 2 if you do nothing) and the main complications that cause people to die are buddy separation and buoyancy issues.

What kevin is suggesting is that when you have an OOA situation (or a massive freeflow which will lead to one that you )

a) run for the hills, separating yourself from your buddy who may be the only person able to help you
b) make an emergency ascent, which in such a situation has the potential to precipitate buoyancy issues and
c) and go OOA somewhere else (maybe the surface if you're lucky) where you are well out of reach of the assistance of your buddy and the ONE functioning scuba unit you have in the immediate vicinity.

In other words, he's suggesting that you pile on the 3 things that we know from accident statistics are the very things that have been known to make things worse FAST and create unnecessary victims.

YMMV but I would personally read that advice with some skepticism.

R..
 
In my opinion solo heroics and feathering are not the answer. The skill and the related standard are focused on a one-size-fits-all solution to a massive freeflow, which is

1) breathe
and
2) get to your buddy
3) end the dive

There is no standard and no training that I can remember for feathering a broken reg before getting to advanced training. Even then, it's usually something that is discussed in the context of a broken reg on a stage cylinder. For a broken back-gas reg, the protocol is usually

1) breathe
2) get the reg shut down
and
3) get to your buddy
4) end the dive

(or some variation thereof that makes the student feel suitably self sufficient).

Suggesting, as above that feathering a broken valve on a single tank and taking some kind of solo action to get to the surface without help is, in my opinion, poor advice.

Proper advice would be to make use of your back-up gear, which is ON YOUR BUDDY'S BACK.

The difference isn't academic. In many fatal accidents, the trigger is an OOA situation (which a massive free flow will become within a minute or 2 if you do nothing) and the main complications that cause people to die are buddy separation and buoyancy issues.

What kevin is suggesting is that when you have an OOA situation (or a massive freeflow which will lead to one that you )

a) run for the hills, separating yourself from your buddy who may be the only person able to help you
b) make an emergency ascent, which in such a situation has the potential to precipitate buoyancy issues and
c) and go OOA somewhere else (maybe the surface if you're lucky) where you are well out of reach of the assistance of your buddy and the ONE functioning scuba unit you have in the immediate vicinity.

In other words, he's suggesting that you pile on the 3 things that we know from accident statistics are the very things that have been known to make things worse FAST and create unnecessary victims.

YMMV but I would personally read that advice with some skepticism.

R..
IMNSHO, the average open water diver would benefit more from simply keeping calm, not panicking and surfacing in a controlled manner while sipping from their reg than from trying to manipulate their tank valve in a stressful situation (which a freeflow is to most of us, even if we've had it before and know that it's more of a nuisance than a crisis)
In My Real-Life Objective Opinion, and coming from an experienced overhead environment -I know that Valve Modulation it's a valuable skill to practice and develop with confidence & competence especially with a non-fixable free-flow, in a worst case buddy separation/poor visibility situation.

Again the motivation is to NOT let breathing gas waste away if you have the ability to take breaths by modulating/ feathering the tank valve. [As an aside, I believe this an easier more viable option in Sidemount and should be taught within this specialty as well].
 
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Part of the problem by keeping one end in your mouth is that a student could potentially be holding their breath. When I demonstrate this, I tilt my head to the right, and bring in my regulator down my left cheek, sip in some air, then slide the regulator back up and I blow bubbles.

Now is this what students should do in the real world? I really don't think so. I think the method of biting down on one side of the mouthpiece and sipping as one ascends makes more sense.
 
this is a skill that open water students should learn during confined pool sessions so that regulator malfunctions as goes into free flow panic will not set in and student is aware that there is enough air available to reach the surface. Would you rather teach student just to ditch weights and quick ascent to surface?. Also with Padi this is just a confined water skill to be done ,not in Open Water training..
 
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