freeflow on 2nd stage...

[oleras]

here is a scenario....30m down, lots of air.....freeflowing 2nd stage. I know the exercise i was thought...breath like drinking water from a tap and ascend, but is kinking the hose and breathing from your octo another way out? even continue your dive (assume your budy has a redundant air supply, no need for your octo)?....Just wondering.....
oleras

 

[scubatoys]

Most times, when faced with a radical free flow, it's the 1st stage causing it - not the second. You just see it in the second. It's normally a failure in the HP seat, and now the intermediate pressure has increased to the point where a reg has to open up to let the pressure out. If you switch to the octo - that will start to free flow.

But even if that was not the case... you can't really "crimp" the hose... that won't work. I'd say it's time to call it a dive.

 

[Diver0001]

here is a scenario....30m down, lots of air.....freeflowing 2nd stage. I know the exercise i was thought...breath like drinking water from a tap and ascend, but is kinking the hose and breathing from your octo another way out? even continue your dive (assume your budy has a redundant air supply, no need for your octo)?....Just wondering.....
oleras

Although it sounds like a good idea in theory you could just as easily make your problems worse by trying to crimp the hose.

If you're concerned about needing to turn off one second stage and not the other then you could consider a Y/H valve or twinning instead.

R..

 

[spog]

If it is a problem with the second stage, won't be be cured by sticking a big, fat finger into it and closing the value manually?


spog

 

[Diver0001]

If it starts freeflowing in your mouth then the air is normally escaping via the exhaust valve. Sticking your finger in the mouthpiece isn't going to change that.

What you are describing may work if the regulator has started freeflowing when *not* in your mouth. In that case covering the mouthpiece with something (finger, hand) will stop the venturi effect that keeps such a freeflow going.

R..

 

[vjongene]

here is a scenario....30m down, lots of air.....freeflowing 2nd stage. I know the exercise i was thought...breath like drinking water from a tap and ascend, but is kinking the hose and breathing from your octo another way out? even continue your dive (assume your budy has a redundant air supply, no need for your octo)?....Just wondering.....
oleras

Here is how I learned it (CMAS):

- signal free flow to buddy
- buddy turns off your tank valve, gives you his/her octo
- you wait a minute or two
- buddy re-opens your tank valve
- if the reg still free-flows, you call the dive
- if all is OK after breathing the reg for a couple of minutes, it was probably a freeze, and if you breathe normally, the reg is unlikely to free-flow again

If you are diving with two full regs, it is much simpler: you switch to your second reg and have your buddy turn off the tank valve for the first. You re-test the first after a couple of minutes.

This all assumes that you are diving in cold water. In warm water (say, >6C), the reg would most probably have had a mechanical failure and you are better off calling the dive.

If your buddy is nowhere near you, then your only option is to ascend while breathing on the free-flowing reg... (unless of course you have two regs and are able to close the tank valve yourself).

 

[DA Aquamaster]

This sounds like a workable idea but, but also sounds better than it really would be in most situations. To do what you suggest would require that both divers know what to do and have the training to successfully accomplish it. At depth it may also be much harder than in training due to the effects of narcosis.

I also do not agree that a freeze flow is unlikely to quickly re-occur. If nothing has changed except the first stage being cold and badly iced after the freeflow with only minor re-warming, the freeflow is indeed likely to re-occur.

Doing this entire evolution in cold water also leaves the buddy's regulator at risk of freezing up due to the increased demands placed upon it while you wait for the first reg to thaw. This could result in you and the buddy both having to ascend together with one or more freeflowing second stages. And, your air is turned off so it is not readily available to you if the buddy bolts for the surface and leaves you.

Then even if it is successfully done, there is the question of just how much air was lost during the freeflow and whether the dive can even be continued that has to be considered.

Personally in a freeze flow situation, I'd ascent immediately. I may consider attempting to continue the dive if I were equipped with properly configured and redundant doubles, but even then I would still most likely call the dive, particularly if it were a deep dive.

 

[jroy017]

This sounds like a workable idea but, but also sounds better than it really would be in most situations. To do what you suggest would require that both divers know what to do and have the training to successfully accomplish it. At depth it may also be much harder than in training due to the effects of narcosis.

I also do not agree that a freeze flow is unlikely to quickly re-occur. If nothing has changed except the first stage being cold and badly iced after the freeflow with only minor re-warming, the freeflow is indeed likely to re-occur.

Doing this entire evolution in cold water also leaves the buddy's regulator at risk of freezing up due to the increased demands placed upon it while you wait for the first reg to thaw. This could result in you and the buddy both having to ascend together with one or more freeflowing second stages. And, your air is turned off so it is not readily available to you if the buddy bolts for the surface and leaves you.

Then even if it is successfully done, there is the question of just how much air was lost during the freeflow and whether the dive can even be continued that has to be considered.

Personally in a freeze flow situation, I'd ascent immediately. I may consider attempting to continue the dive if I were equipped with properly configured and redundant doubles, but even then I would still most likely call the dive, particularly if it were a deep dive.

Actually its quite doable it happened to me doing a deepdive in 45 water with some students. I signalled one student do give me his octo and to turn my tank offf we proceeded to continue the ascent (which we had already started then) turned the tank back on and then continued to surface with my reg. (wich I changed right after)

Of course I had to tell the student thath this was a planned exercise, I still don't know why he didn't beleive me ?

 

[vjongene]

This sounds like a workable idea but, but also sounds better than it really would be in most situations. To do what you suggest would require that both divers know what to do and have the training to successfully accomplish it. At depth it may also be much harder than in training due to the effects of narcosis.

This is the way we trained. If I dive with one of my regular buddies, I know what s/he will do if I free-flow.

I also do not agree that a freeze flow is unlikely to quickly re-occur. If nothing has changed except the first stage being cold and badly iced after the freeflow with only minor re-warming, the freeflow is indeed likely to re-occur.

That's why you test it for a couple of minutes. In most cases, heat transfer from the surrounding water will have melted the ice. If not, you abort.

Doing this entire evolution in cold water also leaves the buddy's regulator at risk of freezing up due to the increased demands placed upon it while you wait for the first reg to thaw. This could result in you and the buddy both having to ascend together with one or more freeflowing second stages. And, your air is turned off so it is not readily available to you if the buddy bolts for the surface and leaves you.

True. This is why the preferred method is to switch regs on the same tanks, and why we always dive with two full regs.

Then even if it is successfully done, there is the question of just how much air was lost during the freeflow and whether the dive can even be continued that has to be considered.

Yes. Forgot to say that it's a good idea to check your SPG before deciding whether it's worth continuing the dive.

Personally in a freeze flow situation, I'd ascent immediately. I may consider attempting to continue the dive if I were equipped with properly configured and redundant doubles, but even then I would still most likely call the dive, particularly if it were a deep dive.

This will always be a judgement call. I have to admit that even though we trained for this, I have yet to be faced with an actual free flow at depth. I agree that in many (most?) cases the most likely outcome would be to call the dive.

 

[AlaskaDiver]

I had my regulator begin to freeflow at 76 ft of water with a water temperature of 43F and moderate visibility. At about 70 ft, I could actually begin to hear the 1st stage behind my head as I breathed, begin to sound a bit strange. The flow in my second stage only got worse. With the air bubbling into my mouth faster, I was able to partially remove the regulator to breathe off of it enough to get my buddy's attention and accept his alt air. I didn't even try to fiddle with the VIVA as my fingers were larger from the gloves and I had a rush of bubbles in my face. We shared air off of his long hose. I love those long hoses!

I read a few of the comments about turning off the tank. Turning off my air on my tank was the last thing I wanted to do. It would have only increased my level of adrenalin and quite possibly panicked me. I still needed the air to supply my BCD as well as my drysuit. My adrenaline was sufficiently pumping at that time as was my buddy's (only found that out later). We both appeared calm to one another. After a few breaths, my breathing slowed sufficiently, I gave the OK sign. I checked my gauge at the 65 ft range after I had given the OK sign and dsicovered that I had 2000 psi remaining and my freeflow was slowing. We spent the next 10 minutes slowly ascending doing a stop at 50 ft and doing our 3 minute stop at 18 ft. Despite having the long hose, it was difficult to maneuver around together - especially at the 18 ft level. Staying down was trickier than I thought. I brought my octo in for service right away.