What-If Scenario's, What would YOU do?

[Marek K]

Since he's talking about (in that part of answer) what he'd do in doubles, you SHOULD have a long hose and bungied backup in that case. Can't imagine anyone is diving doubles with a standard reg and an AIR2

Ah. Point taken.

 

[Web Monkey]

I didn't realize a 1st stage could cause a 2nd to freeflow, you mean like allowing more than 140 psi to pass? that would be bad! In that case, off to my buddy I go, or grab my pony and head up.

In cold water, a freeflow is usually caused by a first-stage freeze-up, which allows too much pressure to get to the second stage. The second stage is designed to let the excess pressure escape. Crimping the hose would probably rupture the second stage hose, unless it's hugely over-engineered.

Edit: If it's a first-stage freeflow and you have multiple second stages, crimping the hose would only cause the other second stage to freeflow.

In warm water a second-stage free-flow is usually caused by a problem in the second stage (full of crud, needs service, damaged, etc.). In that case crimping the hose would work (if you could actually get a good crimp on it).

Terry

 

[ekewaka]

How would you know?

If it is the first stage, then both 2nd stages will free flow. If it is the 2nd stage, it is very unlikely that both would free flow at the same time.

 

[MXGratefulDiver]

Good thread ... I'm going to base my responses on what I think a reasonably new, recreational diver should do ...

You're diving with a group of new OW divers in a murky quarry or other low-vis (5'-10') place at about 70'. You can see your buddy and a few others but they are hard to see.

First off, before you start this dive, you should ALWAYS designate who's buddied up with who ... diving with a group in 5 to 10 foot vis is just a bad idea. So let's assume that you know who your buddy is. That's the only person you're going to care about at this point ... because the other people in the "group" should also have a designated primary dive buddy.

All of a sudden an errant fin-kick takes your mask away and your 2nd out of your mouth, and hurts bad!

Your first priority is to recover your reg ... don't forget to keep an open airway while you're doing this.

Now all of a sudden, you can't see anything, your mask is gone, but you manage to get your 2nd back in your mouth. Now you can't see your buddy, you've probably shot up a bit from kicking.

Well, you can't see your buddy primarily because you don't have a mask on. Can you recover the mask? If so ... or if you are carrying a spare (doubtful if you're a recreational diver) ... replace your mask. If not, open your eyes, put your gauges directly in front of your face, and begin a slow ascent to the surface. Your vis will be limited to a few inches, and very blurry ... but you will be able to make out enough to read your depth gauge if you're holding it right in front of your face ... and at that point it's all you really care about.

If your buddy saw what happened, he or she should be there to assist you. If they weren't paying attention and swam off, they lost you anyway due to the poor visibility, and therefore they should be also making an ascent to the surface once they realize you're missing.

In this case, I would opt not to do a safety stop (since it's not mandatory), but I would make every effort to maintain a slow, steady ascent.

Once on the surface, remain on the surface. If your buddy doesn't show up, summon help.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

Another scenario: You're at 100 feet, cold water, low viz, diving a single 130, and your primary reg freeflows and you can't get it to stop.

Again, from the perspective of a new, recreational diver ... swim to your dive buddy and signal that you want to share air. Once on your dive buddy's backup reg, either reach back and shut down your valve, or signal your buddy to do it for you. Once your valve is shut down, begin an orderly ascent to the surface, as you were (hopefully) trained to do in your OW class.

From the perspective of a new diver, keep things as simple as possible and follow your training. If you want to practice doing free-flow recoveries, do it in shallow water. 100 feet isn't the place to be crimping hoses or playing around with things you've only ever read about on the Internet.

... Bob (Grateful Diver)

 

[NewFloridaDiver]

In cold water, a freeflow is usually caused by a first-stage freeze-up, which allows too much pressure to get to the second stage. The second stage is designed to let the excess pressure escape. Crimping the hose would probably rupture the second stage hose, unless it's hugely over-engineered.

Edit: If it's a first-stage freeflow and you have multiple second stages, crimping the hose would only cause the other second stage to freeflow.

In warm water a second-stage free-flow is usually caused by a problem in the second stage (full of crud, needs service, damaged, etc.). In that case crimping the hose would work (if you could actually get a good crimp on it).

Terry

Thank you Terry! This is something I didn't know, since I'm a warm water diver, (and fair weather sailor, and I don't play golf in the rain.) This thread has brought out some very good information! Can it be made into a subforum so each scenario has it's own thread? Are you the person to ask? Sorry if you aren't...

Rob

 

[Mthelming]

I have a good scenario you are doing a solo dive in moderate visability, slight surge and at a depth of about 40 feet. You then become entangled in a monofiliment fishing net that was not clearly marked on the surface (poachers). This net is tangled in the valves of your doubles rig....what do you do?

I would take out my broad sword and start to slay the dragon .....errr I would use my sheers to cut my way out, if needed remove my gear to get to it easily (doubles at 40' would last a long time) and just take my time.

 

[NewFloridaDiver]

Good thread ... I'm going to base my responses on what I think a reasonably new, recreational diver should do ...

Well, you can't see your buddy primarily because you don't have a mask on. Can you recover the mask? If so ... or if you are carrying a spare (doubtful if you're a recreational diver) ... replace your mask. If not, open your eyes, put your gauges directly in front of your face, and begin a slow ascent to the surface. Your vis will be limited to a few inches, and very blurry ... but you will be able to make out enough to read your depth gauge if you're holding it right in front of your face ... and at that point it's all you really care about.

... Bob (Grateful Diver)

Yes Bob, that is exactly how I see it happening too. Hopefully, on my way up my buddy will have found my mask and brought it to me! Thanks for your input.

 

[piikki]

Another scenario: You're at 100 feet, cold water, low viz, diving a single 130, and your primary reg freeflows and you can't get it to stop.

I was all about shutting the valve even on single until I thought about couple of dives I have done where this could have happened. I have since decided that for me there would be some situations where I would not necessarily do what I'd see as my preferred way of responding (go to buddy's reg, shut valve, maybe reopen to test if freeflow stopped, and ascend).

On some sites I dive the last bit of ascent is done in considerable current. You basically have to hang onto line not to be blown away. Maybe not for dear life but there is a definite chance of separating from your buddy if you make a mistake, at least separating from the airshare. And once you're gone, buddy might not be able to catch up.

I have some tanks that for trim I have to set very low - which makes the valve quite a wiggle to reach. If I was diving a tank that I do not know I can quickly re-open on my own, I would noway go shutting no valves on it underwater! I would rather suffer the obscuring bubbles! I would breathe from my buddy's reg because I don't particularly like breathing a freeflow but at least if I separated from buddy's air source I might have some air left in my tank, and I can get to it too.

Generally in rec diving I do not think it's always safest to go fiddling with the valve. A lot of gas in shut off tank is still no gas when you need the breath right NOW. You better know what you are doing. You might think you are taking of your BC and playing with your tank - and whoosh your weight-integrated BC went to the bottom and you went to the surface etc.

 

[Marek K]

In cold water, a freeflow is usually caused by a first-stage freeze-up, which allows too much pressure to get to the second stage. The second stage is designed to let the excess pressure escape. Crimping the hose would probably rupture the second stage hose, unless it's hugely over-engineered.

Edit: If it's a first-stage freeflow and you have multiple second stages, crimping the hose would only cause the other second stage to freeflow.

In warm water a second-stage free-flow is usually caused by a problem in the second stage (full of crud, needs service, damaged, etc.). In that case crimping the hose would work (if you could actually get a good crimp on it).

Terry

So... other than the fact that either one or else both of the seconds stages would be spewing air, would the behavior be different for a first-stage vs. second-stage freeflow? Similar volumes of air coming out?

Or another way... When they teach you in OW to breathe from a freeflowing reg, you hold the purge button... which would simulate a second-stage freeflow. Easy to breathe from that. How about with a first-stage freeflow?