Stage planning in caves

[rjack321]

for simple math I use the following fill numbers and assume to be in a shallow <100ft cave.

1XAL80 to 3200psi = 80cf (TF=2.5)
2X104's to 3600psi = 280cf (TF=8.0)

total of 360cf

1/3rd for penetration = 120cf

breath whatever tank where ever you want first, depending on your teams decision.

you could:
start with half of your AL80 = 40cf or 1600psi
leave stage behind and dive 80cf or 1000psi on BG for further penetration.
pick up stage on the way out and breath of it or not.

or you could:
breath AL80 empty, leave AL80 behind and use 500psi of your BG for penetration,
pickup empty AL80 on the way out.

or you could
start with BG, use 1500psi on the way in turn around and never touch you stage AL80
in this case your AL80 would be like a bail out bottle.

many options, all depends on your dive, your goal, conditions and team unity.

Could we please keep the answers "DIR". If I wanted to know alternative non-DIR ways of using stages I would have posted the question in the cave diving forum. Thank you, the OP

 

[Jason B]

Finally, once you convert your diving to "stages only", you will find it to be a much more economical use of the gas, particularly if you are diving mix.

So true and we bring a couple tanks with HE in them to transfill to the stages. Since they are pretty much empty, they are easy to transfill into, where back gas, being left at a higher pressure is not easy to transfill into (without a booster which we don't have).

It's great to bring He that cost us .24 per cu/ft instead of paying .50-.60 per cu/ft for it in cave country.

 

[DIR-Atlanta]

or you could:
breath AL80 empty, leave AL80 behind and use 500psi of your BG for penetration,
pickup empty AL80 on the way out.

I wouldn't recommend doing it that way. If you have to do a gas sharing exit, then if you have used your whole stage on the way in, then you will have to share gas all the way out, which will significantly slow down your exit. By leaving the stage at 1/2+200, you can separate the air sharing divers onto their own separate tanks at the stage drop, which allow the team to move more efficiently from that point to the exit.

or you could
start with BG, use 1500psi on the way in turn around and never touch you stage AL80
in this case your AL80 would be like a bail out bottle.

And then you would have to drag a full stage bottle around (unnecessarily) for the whole dive. Personally I would prefer to be less encumbered whenever possible.

 

[rjack321]

Atlanta, on your "stage only" dives how many are you using? 3, 4, more? Presumably you are you scootering all these bottles as well right?

 

[Data]

Could we please keep the answers "DIR". If I wanted to know alternative non-DIR ways of using stages I would have posted the question in the cave diving forum. Thank you, the OP

here we go again, your DIR is better than my DIR.
or did you want the GUE answer?
why didn't you post in the DIR practitioner forum if you want the GUE answer?
and what part about my post is NOT DIR?

 

[DIR-Atlanta]

Atlanta, on your "stage only" dives how many are you using? 3, 4, more? Presumably you are you scootering all these bottles as well right?

I rarely carry more than two stages, plus sometimes an O2 bottle that gets dropped very early in the dive. Sometimes I swim, sometimes I scooter - just depends on the cave and the particular requirements of the dive.

 

[Data]

.... just depends on the cave and the particular requirements of the dive.

isn't that what I just said?

..... all depends on your dive, your goal, conditions and team unity.

I never said which I would and which I wouldn't agree with, my team always makes that decision and I'm only part of it.
But as a thinking diver I know all the options and I thought the OP was asking for that, but was corrected by him and now understand he only wants to know one specific way of doing it "right"

 

[RTodd]

here we go again, your DIR is better than my DIR.
or did you want the GUE answer?
why didn't you post in the DIR practitioner forum if you want the GUE answer?
and what part about my post is NOT DIR?

Lets be clear. Carrying an unused stage is NEVER a DIR answer. Plese refrain from posting non-DIR answers so I don't have to nuke a relatively good discussion by cleaning up all of the misinformation.

(There is the obvious caveat of placing safeties on long exploration dives where back gas isn't enough of a bailout but this was not being discussed.)

 

[Jason B]

isn't that what I just said?

Well, actually no. He was talking about swimming vs scootering, not stage gas management.

 

[rjack321]

here we go again, your DIR is better than my DIR.
or did you want the GUE answer?
why didn't you post in the DIR practitioner forum if you want the GUE answer?
and what part about my post is NOT DIR?

Carrying a "bailout bottle" while breathing backgas would not be a DIR approach at all. I already know that, and every GUE course addressing stages uses backgas last. Stages are disposable, backgas tanks are not.

I don't have a damned clue why we have a main DIR forum and a practitioners forum. This one is viewable by all and I suppose non-DIR divers might be interested in the DIR answers/rationale.

I agree with you that its not entirely clear what the rules of this main forum are. However I thought I was pretty clear that I was looking for DIR answers on stage use, like the protocols which are taught in Cave2 in which I am enrolled for 2008. Sorry you didn't catch that.

My original question...

What are the general GUE/DIR guidelines for "stage only" vs. "stage + some backgas" types of penetrations?