Regulator free flow at 100 feet.

[pasley]

It was cold (46 degrees) but the visibility was 20+ feet.

...I realized that my reg was free flowing. I had no trouble breathing....At about 10 feet, the reg finally stopped free flowing...after an hour+ surface interval, we enjoyed a shallower (45ft or less) 30 minute dive. I used my reg on this dive and had zero issues.

Aqualung website Specs page says this regulator is approved for >10C which is 50F. So you were using a warm water regulator desined for use in water above 50F at 85 feet and 45F degrees. Result appears to be the classic symptoms of a first stage freezing. A regulator that freeflows at 85 feet and 46F water but works fine in the shallow (warmer water)..... Swimming looking for an object it is possible you were breathing a little heavier than normal. Not all regulators are Coldwater and/or high performance regulators, particularly the lower cost recreational regulators. Go ahead and have it checked by a technician, but I bet he finds it working just fine, like you did in the second dive were you stayed in the warmer water at 45feet.

I stayed calm and then swapped out to my octo. ..[/QUOTE=Mikeguyver;7158198] Why? You are going to loose that air anyway, why not use it?

So here is what I learned.

• ...In hindsight, if I had kept the free flowing reg in my mouth rather than swapping to my octo, I would have lost less air.[/QUOTE=Mikeguyver;7158198] Yep, just like your training taught you too. Continuing to use the free flowing regulator not only saves air, but reduces the work load on the first stage which can contribute to freezing.

Just my $0.02,

 

[doctormike]

At that point, you recognized correctly that a strong freeflow will empty a tank fairly quickly. You switched to the octo -- did you try any maneuvers to make the freeflow from the primary reg end? Sometimes banging on the reg, or cycling the purge button, or even exhaling sharply through it can solve the problem.

I agree with Lynne that when single tank diving, stopping the free flow is especially important. If it was a significant free flow, and if it didn't stop with standard maneuvers, you can lose all of your gas pretty quickly. One option in that situation would be to kink the hose of the free flowing regulator, then just use your backup reg ("octopus").

You were under a deco obligation (because 5 minutes at 20 feet is not a "safety stop"). HERE is where the biggest learning in the event comes in. .... Surfacing with a deco obligation, to orient yourself, is a high risk action. You got away with it.

Amen!

 

[FinnMom]

If my buddy or any other donator is available, I would switch to their backup and shut my air off. This because the fast-flowing air cools both 1st stage and 2nd stage more and more as it flows, usually making the freeflow worse and worse (bloody fast too). Or at least that's been my experience - of course that could be just because virtually all my freeflow experience is from very cold water and freeflows probably caused by excessive exposure to freezing air temps, or these temps + moisture.

I have learned that a freeflow reg, when shut off and allowed to warm up a minute or 3, will usually work just fine.

Not anything you asked but BTW
Maybe I'm just not used to the norms of how deep people go w/ basic gear in better vis, but I would have been a bit hesitant to go to 100 ft in a buddy pair both diving single tanks. Think about it: if at the end of your planned bottom time something went seriously wrong, forced you two to share air, also delayed your departure upwards for a couple minutes (getting calmed down and squared away) and caused stress that raises your SAC 50% (pretty normal). Would you have had enough gas to make a safe ascent? A single tank used by 2 divers gets empty real fast below 70-80ft.

You did a nice job handling the freeflow with calm + clear thinking. In the end bent on the surface is still better than OOA below the surface. Next time I bet you will be much more aware of your budy's location and proximity

 

[Kevrumbo]

If my buddy or any other donator is available, I would switch to their backup and shut my air off. This because the fast-flowing air cools both 1st stage and 2nd stage more and more as it flows, usually making the freeflow worse and worse (bloody fast too). Or at least that's been my experience - of course that could be just because virtually all my freeflow experience is from very cold water and freeflows probably caused by excessive exposure to freezing air temps, or these temps + moisture.

I have learned that a freeflow reg, when shut off and allowed to warm up a minute or 3, will usually work just fine.

Not anything you asked but BTW
Maybe I'm just not used to the norms of how deep people go w/ basic gear in better vis, but I would have been a bit hesitant to go to 100 ft in a buddy pair both diving single tanks. Think about it: if at the end of your planned bottom time something went seriously wrong, forced you two to share air, also delayed your departure upwards for a couple minutes (getting calmed down and squared away) and caused stress that raises your SAC 50% (pretty normal). Would you have had enough gas to make a safe ascent? A single tank used by 2 divers gets empty real fast below 70-80ft.

You did a nice job handling the freeflow with calm + clear thinking. In the end bent on the surface is still better than OOA below the surface. Next time I bet you will be much more aware of your budy's location and proximity

I agree . . .

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 handle. 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

All it takes is practice (and IMHO --should be a mandatory skill taught in basic open water courses. . .)

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 exhausting of precious breathing gas. If you have a pre-dive Rock Bottom Gas Plan and you know how much pressure your tank has during all phases of the dive --you lose or become separated from your Buddy for an instant-- then why would you let vital breathing gas bubble away in all it noise & vision obscuring fury 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, spending a moment on the chance that your buddy will find you again? And if not able to find your buddy, then how about a nominal ascent with a safety stop while still modulating your tank valve as needed for breaths?

Difficult technique & skill to coordinate, but can be achieved with lots of practice. . .

 

[TSandM]

We have been over this before. The feathering technique is NOT a safe one to recommend to the average recreational diver. Most divers can't reach their own valves to begin with; those who can, often do it with great difficulty, and not nearly securely enough to depend upon it for their breathing gas. When BOTH sharing gas with a buddy AND breathing the free-flowing reg while ascending are available, there is NO - repeat NO - reason to feather the valve on a single tank.

 

[doctormike]

We have been over this before. The feathering technique is NOT a safe one to recommend to the average recreational diver. Most divers can't reach their own valves to begin with; those who can, often do it with great difficulty, and not nearly securely enough to depend upon it for their breathing gas. When BOTH sharing gas with a buddy AND breathing the free-flowing reg while ascending are available, there is NO - repeat NO - reason to feather the valve on a single tank.

Right, the danger is that you could take a bad situation and make it worse, if you shut off the valve and can't turn it back on again...

 

[alewar]

If you are diving in cold water you should consider using two first stages so that you can shut down one in case of free flow.

 

[tursiops]

Aqualung website Specs page says this regulator is approved for >10C which is 50F. So you were using a warm water regulator desined for use in water above 50F at 85 feet and 45F degrees. Result appears to be the classic symptoms of a first stage freezing.

Not likely a first-stage freeze up....that would produce a significant gas loss and both second stages would be affected.

---------- Post added June 30th, 2014 at 05:49 PM ----------

One option in that situation would be to kink the hose of the free flowing regulator, then just use your backup reg ("octopus").

Have you ever tried this? Especially with modern hoses?

 

[bada3003]

IMO, Mikeguyver stayed calm and did very well under the circumstances. But I'm puzzled by one item (maybe I misread) which I hope you can clarify.

In 40s temp at Mermet Springs with an AL Titan (which, by default, is not environmentally sealed although there's a kit), it seems likely that the 1st stage froze which triggered the free flow. This is consistent with the free flow ceasing when you reached 10 feet. But if it was the first stage free flowing, switching to an octo shouldn't help. It just connects to another LP port on your 1st stage so should free flow as well. Question: Are you saying that the octo did not free flow?

---------- Post added June 30th, 2014 at 05:59 PM ----------

Indeed. Feathering with a backmount for rec divers? If sidemount, perhaps. Let's be realistic here.

We have been over this before. The feathering technique is NOT a safe one to recommend to the average recreational diver. Most divers can't reach their own valves to begin with; those who can, often do it with great difficulty, and not nearly securely enough to depend upon it for their breathing gas. When BOTH sharing gas with a buddy AND breathing the free-flowing reg while ascending are available, there is NO - repeat NO - reason to feather the valve on a single tank.

 

[doctormike]

--


Have you ever tried this? Especially with modern hoses?

No, I haven't. Heard about it, thought that it might be a good option in that particular situation (free flowing second stage, unable to stop otherwise, single tank), but I'll take your word for it if you have tried it and it didn't work.

I might still try it if I was in that situation and had a standard rubber hose, though...!

M