Regulator free flow at 100 feet.

[dumpsterDiver]

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.

I think I agree, but aren't you the one who previously recommended that a buddy completely shut down the freeflowing tank valve, leaving the victim with the air off and breathing from the octopus of the rescuing diver as they ascend together?

Also, the whole issue of noise and obstructed vision. The diver could simply take a quick breath from the reg and then hold it at arm's length as they slowly exhale (and repeat).

This would not seem difficult at all, and would use the air more efficiently... but definitely does tie up a hand..

 

[tursiops]

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

Actually, no, I haven't tried it, nor have I ever heard of anyone doing it! I assume it would only work with the old rubber hoses anyway.

Sent from my GT-P3113 using Tapatalk

 

[Mikeguyver]

This is great feedback. Thanks.

The octo worked fine while the primary was free flowing so it was the second stage. I tried fast inhales and was banging it on my hand too. I thought about kinking it but figured that it wouldn't work. Putting my thumb over the mouthpiece only sent the air out the exhaust tee. I looked at my computer and the total dive time was 13 minutes. I got to depth at 5 minutes and was back at 11 feet at 7 minutes. I realize that I was lucky and could have done some things differently. I now know that it takes longer to drain a tank and should have put the reg back in once I realized that I couldn't stop it while I was using the octo. I could have hung out at a shallower depth easily and should have rather than surfacing. I haven't had any issues with the reg at Mermet below the thermocline before. Once again, I appreciate your feedback. Mike

 

[bada3003]

...
The octo worked fine while the primary was free flowing so it was the second stage. ...

Thanks for the clarification. I know it's possible in cold waters for the second stage to freeze up w/o the first stage doing so, but I was under impression that it's far more likely that the opposite holds. Especially in mid-40s temps where adiabatic cooling can have a significant effect in the 1st stage where the pressure differential is high.

 

[Storker]

I know it's possible in cold waters for the second stage to freeze up w/o the first stage doing so, but I was under impression that it's far more likely that the opposite holds. Especially in mid-40s temps where adiabatic cooling can have a significant effect in the 1st stage where the pressure differential is high.

IME, it's usually the second stage that freeflows. It's a fairly common phenomenon up here when winter, spring or autumn diving, especially if the air is cold: Someone in your group surfaces, and during the interval from they surface until they are ashore or on the boat, the primary second stage starts to freeflow and can't be stopped until the tank is closed.

Although I've seen quite a few second stages freeflow due to the cold, I've never seen a first stage freeflow, even in temps down to 3C water / -10C air.

 

[TechDeep]

Just something to think about if you are thinking that you may again run into the same situation. Please reach out to an instructor that is familiar with the conditions common to the area you dive, the use of such devices, and the required training. If you are running into deco obligations, you have crossed a line that should only be crossed with additional training.
Inline Shut-Off Valves - Dive Gear Express

 

[FinnMom]

just for the record, i did not suggest feathering. I said get gas from someone else, then shut down your flowing reg. If you re-open your tank several minutes later the freeflow may (or may not) be just fine.
I wouldn't mess with feathering unless it was just one side of a doubles setup, or a stage/pony bottle. A single tank on your back just isn't easy enough to reach, esp. for a rec diver who has never tried this before.

 

[Jim-SAR]

Surfacing with a deco obligation, to orient yourself, is a high risk action. You got away with it. And, with a five minute obligation, you might have been better off remaining on the surface, than going back down -- because if you were going to become symptomatic from DCS, you'd rather do it on the surface, where you are easily reached by help, than underwater, where you might not be found.

I've read back through the OP's post, and although he went to 100 feet, I can't see how he incurred a deco obligation. Per the PADI RDP Tables, the NDL for 100' is 20 minutes. The RDP says a safety stop is required for any dives to 100' or more, but isn't the whole point of NDLs to give a depth/time reference to allow for a direct ascent (slowly) to the surface, as long as you remain within these limits?

I agree with you, that you should always do a safety stop if possible. Maybe it's just the terminology that's bothering me (deco vs. safety). To me, an true deco obligation is where you have exceed a limit, and you no longer have the option of going to the surface without DCS complications.

 

[TSandM]

The OP said his computer gave him a 20 foot ceiling and a five minute stop. Perhaps this is the behavior of such a computer for non-mandatory "safety stops", but I haven't encountered a computer that would do this. Anything I've used, if it gives a ceiling below 15 feet or a time over 3 minutes, it's a deco obligation.

We don't know if there had been an earlier dive, which would affect the NDLs for a second one, particularly a relatively deep one.

 

[bada3003]

Norway is pretty cold so your comments are due serious consideration. But it's counter to what I know. It's just basic physics. Also, you see it in the reg manufacturers who build "cold water regs" (mostly diaphragms with environmental sealing) but almost never cold water 2nd stages. For second stages, what you can do is put a metal purge cover which facilitates heat conductance w/ the relatively warmer water. That's about it. AL has a cold water 2nd stage in their glacier model but it's just a metal cover w/ an expanded metal hose adaptor to, again, to promote heat conductance w/ warmer water (low 40s/high 30s is cold but obviously not freezing). I have it but use SP S600 and Hollis DC212 which work fine in both cold and warm waters.

IME, it's usually the second stage that freeflows. It's a fairly common phenomenon up here when winter, spring or autumn diving, especially if the air is cold: Someone in your group surfaces, and during the interval from they surface until they are ashore or on the boat, the primary second stage starts to freeflow and can't be stopped until the tank is closed.

Although I've seen quite a few second stages freeflow due to the cold, I've never seen a first stage freeflow, even in temps down to 3C water / -10C air.