sharing air in cold water

[FoxHound]

Yes, just set the IP to mid-range and the secondary to "normal breathing", not "anticipates each breath"...

Actually I set the IP a bit lower then mid-range....and yes secondary to normal breathing. I find that the second usually only freezes up if it was wet on the surface (IE dont breathe it till its under the water dealy)

I like the IP a bit lower as when you start to get that cold water ip creep, it doesn't go from bad to worse right away.

ive seen apex, oceanic, zeagle, scuba pro, and hollis all free flow, Haven't seen my wifes sherwood blizzards free flow.....my try and get em to do it while the water is still at freezing haha

 

[northen diver]

I also dive the blizzards and most of my dives are cold water. I never had a freeze up on my blizzards since I started diving the blizzard back in the 90's. I keep the IP at 125 which is the bottom end for the Sherwoods. I had grapefruit size ice balls on my 1st stage and it was still bleeding with that much ice build up. I seen apex and zeagle freeze on a frequent basis.

I did try and get my first stage and second stage to free flow and no success. I breathed on my second stage in single digit temps at the surface, air shared at depth, purposely tried to over breath the reg at depth, purged my first stage at depth and they just dont free flow, I believe because of the low IP settings.

I surely get people though telling me that my 1st stage is leaking because of the small bubbles coming from it. When I tell them that is normal, they just look at me funny and walk away.

 

[Scuba-dan]

I think those situations are the ones where you ought to be thinking long and hard about redundancy. Whether it's a pony bottle or a set of doubles, I think it's a good idea to avoid a double draw on a single first stage. This is one of those things where planning prevents problems.

I'm just curious on your statement, how would a set of doubles really do to help you in a free flow? I can see the pony bottle.

 

[kirasir]

edited..

 

[rhwestfall]

I'm just curious on your statement, how would a set of doubles really do to help you in a free flow? I can see the pony bottle.

modern doubles with an isolation manifold means first stage on each tank, and cross-over/isolator.....

or in the case of an h-valve....


(credit to Dive Gear Express for the images)

 

[eponym]

I'm just curious on your statement, how would a set of doubles really do to help you in a free flow?

To amplify on the previous post . . .

Using doubles in a common configuration,
You donate your primary, which is attached to your right tank's first stage.
You breathe from your secondary/alternative/octo, which is attached to your left tank's first stage.
Each of your two first stages is only seeing one downstream demand (one second stage).
The assumption is that a freeze-up will therefore be less likely.
Should one first-stage freeze, you could close the isolator valve and resort to buddy breathing.
But (in my experience) someone regularly diving doubles in cold water most likely has the training and experience needed to select first stages that are unlikely to freeze.

I know that the opening post was about how to minimize freeze-up when someone has to share and two are breathing off one first stage. A lot of the good suggestions in this thread are about alternative gear choices that can avoid that scenario. They don't directly address the question first asked, but they do open up the discussion.

 

[TSandM]

Even more than that, if you are diving doubles and one of your regulators free-flows, you can shut that post and breathe off the other regulator, so you don't have to go to anybody else for gas, nor do you lose a catastrophic amount (assuming you are good at valve shutdowns).

 

[lowviz]

...//... I find that the second usually only freezes up if it was wet on the surface ...//...

I get yelled at for that a lot. -holding the secondary in the air instead of underwater while I'm yapping with someone...

 

[FoxHound]

haha i used to do that, until one day,I had just surfaced and i was sitting on the edge of the ice in the water, put the reg in my mouth ready to go back down and got a nice mouthful of ice.....not so pleasant

 

[Scuba-dan]

Even more than that, if you are diving doubles and one of your regulators free-flows, you can shut that post and breathe off the other regulator, so you don't have to go to anybody else for gas, nor do you lose a catastrophic amount (assuming you are good at valve shutdowns).

I did not know that. that makes a lot of sense.

Thanks guys.

---------- Post added March 15th, 2013 at 01:57 PM ----------

modern doubles with an isolation manifold means first stage on each tank, and cross-over/isolator.....

View attachment 149996or in the case of an h-valve.... View attachment 149995


(credit to Dive Gear Express for the images)

The things you learn here.... that makes lots of sense now.