Gas Sharing in Deco

[cadet diver]

For those who are doing deco diving what is your procedure for an out of gas situation in deco? If your buddy for whatever reason found that they did not have enough deco gas, would you share yours with them? In my trimix class we had 5' hoses on all our deco bottles to be able to share with, or we could just pass a bottle. The problem is then you blow your own deco too.

 

[Rick Murchison]

The short answer is that you always have a backup deco plan - usually enough reserve back gas to complete a deco on that gas. But specifics vary from dive to dive. Anyway, it isn't a big deal if you've planned and equipped yourself correctly. (other than a looooong hang)
Rick

 

[Northeastwrecks]

Agreed. I always carry a "no deco gas" plan on my slate. In most cases, my dive plan will handle this (albeit with very little margin).

I'd rather share deco gas and shoot a bag asking for another bottle of whatever's on board than leave a buddy.

 

[cadet diver]

Since problems tend to snowball, if one did not have enough gas for both divers to do full deco. For instance the situation in the Last Dive, would you share your gas and blow your deco as well? What will buddy breathing do to your deco. Or am I making this into something its not.

 

[Spectre]

cadet diver once bubbled...
Since problems tend to snowball, if one did not have enough gas for both divers to do full deco. For instance the situation in the Last Dive, would you share your gas and blow your deco as well? What will buddy breathing do to your deco. Or am I making this into something its not.

It's tough to use "the last dive" as examples, since there was planning and gas management problems to begin with in those situations. e.g. you carry all your gas with you... you don't leave it somewhere to loose.

I'm not doing deco diving yet; but: What Rick and Dan are saying is that you have more than one plan. You have your plan with your deco gas, and then you have a backup plan in case you loose your deco gas. When planning your bottom time, you plan it in such a way that if you loose your deco gas, you still have enough back-gas to do the 'no deco gas' plan.

In other words, if your EAN50 stops are 1 @ 40, 1 @ 30, 8 @ 20, and your 'no deco gas' stops are: 1 @ 40, 3 @ 30 and 13 @ 20; you need to make sure you hit your 40' stop with enough back gas to do those extended stops.

 

[Bottomfeeder]

Rick Murchison once bubbled...
The short answer is that you always have a backup deco plan - usually enough reserve back gas to complete a deco on that gas.

That might work for something like 100 ft for 70 minutes on EAN32, but you will never have enough backgas to deco out of a deeper dive according to a software generated plan.

Since we carry our gas in the ocean, we are not going to lose all of it. You just do the best you can with what you have. If you do the lower stops right, your chance of getting out unscathed is pretty good even if you completely lose one deco bottle (not likely). I had a buddy lose a first stage seat once, and he just did his deco by turning the bottle on and off. There are also other divers around, and you can get their bottles as they complete their decos. In the ocean, we always limit our exposure because of the number of variables. We don't incur 2 hour deco obligations unless we have extensive support.

I find that understanding decompression so that you can make intelligent decisions when it goes wrong is more effective than carrying a slate with 6 different plans on it. If you carry 6 plans, you will encounter the 7th situation.

As you might have guessed, deco diving is something that needs to be done gradually if it is to be done safely.Taking a trimix class is only a first step, you need to build experience with progressively deeper and longer dives.

Dive smart
bot

 

[Doppler]

cadet diver once bubbled...
For those who are doing deco diving what is your procedure for an out of gas situation in deco? If your buddy for whatever reason found that they did not have enough deco gas, would you share yours with them? In my trimix class we had 5' hoses on all our deco bottles to be able to share with, or we could just pass a bottle. The problem is then you blow your own deco too.

One 'correct' procedure and one that has been taught and practiced successfully for many years is to buddy breathe the deco gas. This is also useful if someone stages the incorrect gas at, let's say the 140 foot stage! (Are you out there Ralph?)

But what facinates me is what on earth do you mean when you say by sharing gas you blow your own deco?

DD

 

[WreckWriter]

Doppler once bubbled...
One 'correct' procedure and one that has been taught and practiced successfully for many years is to buddy breathe the deco gas.

The scary thing is that we had multiple posts on this topic and you're the first one to mention this!

Another scary thing is that buddy breathing is an optional skill in at least one agency, has been for a long time. I wonder what percentage of divers don't even know how to do it?

WW

 

[Rick Murchison]

Bottomfeeder once bubbled...
but you will never have enough backgas to deco out of a deeper dive according to a software generated plan.

Perhaps you may not. But I will. Whatever it takes. That may mean a "cave" protocol with a continuous guideline back to prestaged hang tanks, but I will *always* be able to complete deco with the loss of any single bottle, be it stage, deco or back gas. (that may mean gas sharing with a buddy at some point, but not "buddy breathing a deco bottle") If the plan does not accomodate a lost gas scenario safely it is a bad plan and I won't dive it.
Any GUE trained divers out there handy with the "DIR" solution? I'm curious...
Rick

 

[Rick Murchison]

cadet diver once bubbled...
Since problems tend to snowball, if one did not have enough gas for both divers to do full deco. For instance the situation in the Last Dive, would you share your gas and blow your deco as well? What will buddy breathing do to your deco. Or am I making this into something its not.

This question presupposes diving a bad plan in the first place. Don't dive a bad plan and you won't have to answer it.
Rick