Shutting off a single tank diver's air supply in a free-flow?

[Nemrod]

There was a thread not long ago where it was asked about equipment failures. It appears to me with all these free flowing regs and failing equipment you guys might want to upgrade.

Scubatoys did a video which confirmed what most people already knew, a LP failure or free flowing reg can rapidly empty a tank. Knowing this fact why not begin the ascent immediately and figure out what is wrong in the safety of the surface.


So, let's see, we are going to trouble shoot the problem, at least 30 seconds or more, feather valves, another indeterminate amount of time, oops, your buddy has a free flowing reg also, oh dear. Seems whatever caused your reg to free flow now has his free flowing. Now, are you going to hang out in 70 feet and continue to trouble shoot and play with valves are might you head to the surface where you should already be?

You could kink the hose.

N

 

[SparticleBrane]

mentally deficient lunatics that lack the mental capacity to walk and talk at the same time.

I'm fairly certain you just perfectly described most politicians.

 

[Nemrod]

Couple of preliminary comments --

Re the comment about gas planning by Nemrod -- I don't know who taught you the "Rule of Thirds" but my understanding is that it only applies when you HAVE to get back to your starting point (i.e. the upline in a non-overhead environment). On a drift dive the "rule" is all available gas -- you dive until you hit your minimum reserve and then you surface because the boat is there to pick you up; on a shore dive the "rule" is halves -- it's nice to get back to where you started but you don't have to. In those two cases, you can have your free flow late in the dive and your tank will probably be empty very quickly!

The best alternative is NOT to try to suck gas from a fire hose while trying to keep your mask on but to sip it from someone else's working reg.

Wow, I have no response to all of your calculations. You do have to return to where you began in every dive--the surface. It is perfectly acceptable to modify the rule to suit as long as it leaves sufficient reserves. I contend that the typical surface with 300 psi is not sufficient and violates the rule.

As to who taught me, I figured it out myself. That is a novel concept I know but it works for me, apply my mind to the problem rather than quoting "my instructor said" and since he is dead now probably 30 years that could be a problem. Oh well, guess I just have to figure it out myself, try it sometime.

Mr Sting is right on, if you suspect the free flow is the result of ice formation, you might consider shutting down to allow it to defrost. That might be kind of like when I had carb ice over the Big Thicket at 12,000 feet in the old Tiger and found myself (pilot error as usual) gliding. Good thing I found a runway. The free wheeling engine restarted just as the mains kissed down, finally defrosted. I figure the reg would "defrost" about the time I hit the surface on a CESA so I still therefore contend, begin an immediate ascent and play mechanic on the surface. Again, single tank, no deco, no overhead. If those assumptions change than everything changes including the fact that a single tank diver does not generally belong in overhead.

Oh well, y'all have fun with this, see you topside.

N

 

[nereas]

Only those run by mentally deficient lunatics that lack the mental capacity to walk and talk at the same time. What next? Attempted suicide if you feather your own valve?


Not necessarily if its at the start of a dive and its turned off quickly.


Oral inflate. Its taught from day 1 in all courses.


You have enough time.


So think about getting on an AAS while getting the valve turned off to defrost.


Why bother? Orally inflate jacket. Float happily.


Firstly why not just share air and do the stop? Secondly, a safety stop is optional. It doesnt preclude further diving. Its not a mandatory stop.


Someone else mentioned thirds here - that isnt guaranteed to help. If the guy with the freeflow has a higher gas consumption than the other guy its not impossible that 1/3 gas will not be enough for 2 divers.

These are precisely the decisions that I would expect such a mentally deficient lunatic as you yourself mentioned to make, in fact. Primarily because this kind of person does not comprehend the risks that are now compounding with every ticking second of passing time.

A freeflowing reg is not so unusual. Hopefully in your open water class you yourself learned how to breathe from it while ascending carefully to abort your dive.

I know that these kind of posts are the kind that should be ignored. But before pressing the "ignor String" feature, I wanted to briefly respond.

 

[John_B]

Say the free-flow doesn't happen to YOUR buddy, but you're on a dive with a bunch of newly certified OW divers (some of you might avoid these dives like the plague , but nevertheless) and one of their regs starts to free-flow, rather than approaching their buddy they approach you and signal to air-share, etc. Would you turn their tank off in this situation?

No, I wouldn't turn off their air. That's really not my call. And besides, they aren't really my buddy, though I would still help.

I would give them a working regulator, exchange OKs, and then ask (signal, really) to find out if they wanted to turn it off or not, and ascend normally. I would have no problem doing a normal air sharing ascent -- bubbles and all -- if that's what they wanted to do. I most definitely wouldn't want a new diver ascending on a freeflowing reg if they didn't have to. We were all taught to "sip" off a freeflowing regulator in OW training but what if they forget and don't breathe sufficiently on ascent due to all the air being forced out of the regulator?

Besides, a freeflowing first stage will empty a tank a LOT faster than some people seem to be implying. That tank is going to be empty pretty quickly.

BTW, I dive with new divers and with experienced divers. I just use a different set of parameters (i.e. more conservative) until I get a chance to see how an unknown diver behaves underwater. 30' reef dives with brand new divers are some of the most fun times I've had underwater. Their excitement is infectious, and it reminds me why I got into this crazy hobby in the first place.

HTH

 

[String]

These are precisely the decisions that I would expect such a mentally deficient lunatic as you yourself mentioned to make, in fact. Primarily because this kind of person does not comprehend the risks that are now compounding with every ticking second of passing time.

What risks? Gas is running out. Thats an easily quantifiable (and easily remedied) problem.

A freeflowing reg is not so unusual.

Correct.

Hopefully in your open water class you yourself learned how to breathe from it while ascending carefully to abort your dive.

In most classes you're taught to think and not always have a blind, often unnecessary response to a problem. If you want to abort the dive then feel free. If you want to see if it'll defrost so you can continue, feel free. Both methods are perfectly acceptable to anyone with an IQ approaching room temperature.

 

[dumpsterDiver]

Interesting discussion.... I just recalled an incident many years ago, when my buddy's only second stage hose exploded, right at the second stage. It made a huge boom and when I looked over at him, he had a second stage in his mouth and 2 inches of frayed hose...It looked exactly like a cartoon figure with an exploded cigar.

We were diving in about 20-24 feet of water and I immediately jumped on his back, shut his valve down and then waved bye-bye to him as he swam up. I was laughing too hard to even consider offering him any air from my reg. Before the dive, his hose displayed a big anurism and he dove it anyway. Obviously shutting down a tank might also depend on the depth.

 

[Ice Mike]

Well, thank you everyone, this is certainly interesting. The only thing I'm wondering is if the scenario is changed a bit will the answers differ - so, here goes:

Say the free-flow doesn't happen to YOUR buddy, but you're on a dive with a bunch of newly certified OW divers (some of you might avoid these dives like the plague , but nevertheless) and one of their regs starts to free-flow, rather than approaching their buddy they approach you and signal to air-share, etc. Would you turn their tank off in this situation?

Same environment as before, single tanks, no redundant air sources (aside from buddies), no deco dive, no overheads.

Yes I know there are a bunch of assumptions here, like that you're on that dive to begin with, the diver approached you and not his/her buddy, that the diver isn't panicking or attacking you for air, etc, but I would think that this is a plausible situation and I wouldn't be surprised to see a new diver go after a divemaster or more experienced diver for air should it happen to them.

Plz add another assumption.

Am I joining a guided dive or are we a random group of divers at the same spot in the ocean?

If guided dive, I would see if I can off load the diver to the guide before going up with him. Not just because I would like to finish the dive with my buddy but also because I would assume the guide has more experience with these matters.

 

[Tigerman]

They do this on TV and in the movies, but really not a good idea, actually.

Breathing from a freeflowing reg works perfectly fine, I did this as late as 22nd of december..
Actually "perfectly fine" is somewhat of a exxaguration as it does feel a bit weird, but you get the air you need without much hassle. The air also disappear surprisingly slow so unless youre quite low on air to begin with its not much of an issue..

As for why my reg freeflowed..
Water temps so cold the water froze up behind me as I was working on and near the surface. Probably breathed the regulator both above and under the surface, which is not a good thing to do in cold weather..

 

[sabbath999]

I was laughing too hard to even consider offering him any air from my reg. Before the dive, his hose displayed a big anurism and he dove it anyway. Obviously shutting down a tank might also depend on the depth.

Shame you didn't have a camera with you (On the surface of course, I don't expect you to be asking your buddy to stop without any air so you could take his picture).