For those using bottom stages...

[dsteding]

I think the general consensus on that old thread was, "don't"

But where do you draw the line? A T1 diver using a bottom stage to get 2x tech1 dives off a set of doubles?

In my mind the line is one versus two bottles. I can dive a stage just fine in the 2nd dive after a T1 dive, for instance.

But, carrying two bottles gets more complex, so no T1 diver using a bottom stage to get 2 T1 dives for me.

Of course I'm still a baby-in-training tech diver, but that attitude won't change much for a long time, probably until I get some training on multiple bottles.

 

[rainman_02]

A stage, properly used in OW is not a big deal.

It's pretty freaking easy (recreational):

1) Dive #1, take your stage and backgas. Breathe the stage first, monitor the usage, switch to backgas at some pre-determined gas point. Breathe backgas to finish dive. You might have used up 10-15 cuft of backgas if you did 30 minutes at exactly 100'.

2) Dive #2, take your backgas. Dive.



For two T1 dives, it is almost that simple. You've been trained how to dive with "one bottle." You have to remember, it is about exposure...and limiting yourself. Is an additional bottle of backgas going to increase your exposure? Not really.

You know how to do a bottle switch, right? Those steps are proper bottle verification. If you do that with every bottle you touch, then you have completely uncomplicated the "complicated" process of a T1 dive with a stage so you can get two dives out of one set of doubles.

Dive #1, take your stage, deco, and backgas. Breathe the stage first, monitor the usage, switch to backgas at some pre-determined gas point. Breathe backgas to finish bottom time. Switch to deco gas at appropriate depth. You might have used up 30-35 cuft of backgas if you did 25 minutes at exactly 150'.

2) Dive #2, take your backgas and deco. Dive.




I'm with RTodd. Stages are pretty easy in OW.

 

[MonkSeal]

A stage, properly used in OW is not a big deal.

I'm with RTodd. Stages are pretty easy in OW.

It's easy and it's not a big deal when somebody shows how and when you learn it. There are few details and tricks that can make you life easier or can make your dive PITA. Like: order of clipping (SPG, bottles, ...), easy stowing when you have two bottles, light bottle supporting heavy one, etc. It's not rocket science but it's easier when you're shown.

IMO:
- Recreational not trained to use any stage - too complicated; I don't say that this can't be learnt but I'm not sure if this is neccesarry for recreational dive.
- Tech-1 can do this but there's a risk of multiple stage bottles, switch on surface procedure.

I don't see why you claim stages are pretty easy in OW. Does this mean they are complicated in cave?

BTW When we perform Tech-2 dives we usually go first for bigger doubles and then add bottom stage. However, this is not a strict rule and actual choice depends on many factors.

 

[RTodd]

First, stages are pretty easy to dive if everything else is squared away. However, my points were that (a) you don't even need doubles for the proposed dive, (b) if you haven't ever used stages/ deco bottles using them for logistical convenience is a bad idea, and (c) under the current GUE regime, you need to be at a minimum T2 before your dive depth is going to necessitate the extra gas of a stage for a single dive.

And yes, the use of stages improperly will get you killed in caves much faster than in open water where you basically breathe them empty and then go to back gas. In caves, you are often using multiple stages so you have to work out what amount of backgas must be retained for a reserve and when safety bottles are needed. You also have to balance speed in vs. out, drop times, etc. in determining how much to breathe of each stage i.e. 1/2 + X. None of this is rocket science but it generally takes some experience to get it right in a cave. To put it in perspective, I generally just dive with Chris and Danny in Akumal because the logistics of arranging a trip with the few people I know that are qualified to do multi stage scooter dives is really difficult.

 

[MonkSeal]

First, stages are pretty easy to dive if everything else is squared away. However, my points were that (a) you don't even need doubles for the proposed dive, (b) if you haven't ever used stages/ deco bottles using them for logistical convenience is a bad idea, and (c) under the current GUE regime, you need to be at a minimum T2 before your dive depth is going to necessitate the extra gas of a stage for a single dive.

Totally agree.

And yes, the use of stages improperly will get you killed in caves much faster than in open water where you basically breathe them empty and then go to back gas. In caves, you are often using multiple stages so you have to work out what amount of backgas must be retained for a reserve and when safety bottles are needed. You also have to balance speed in vs. out, drop times, etc. in determining how much to breathe of each stage i.e. 1/2 + X. None of this is rocket science but it generally takes some experience to get it right in a cave. To put it in perspective, I generally just dive with Chris and Danny in Akumal because the logistics of arranging a trip with the few people I know that are qualified to do multi stage scooter dives is really difficult.

Thanks for clarification.

 

[lamont]

First, stages are pretty easy to dive if everything else is squared away. However, my points were that (a) you don't even need doubles for the proposed dive, (b) if you haven't ever used stages/ deco bottles using them for logistical convenience is a bad idea, and (c) under the current GUE regime, you need to be at a minimum T2 before your dive depth is going to necessitate the extra gas of a stage for a single dive.

70 mins @ 100-120 fsw can be done with a single O2 bottle for deco, but is right on the dot at thirds for double-130s and a 0.60 cuft/min SAC. add being 6,000 ft away from your entry point when you turn and under boat traffic and then a stage makes for a nice gas buffer.

 

[Vie]

I started using an AL80 stage after T1 for a few T1 level dives. Yes, it was for "for logistical convenience" and yes it did very slightly complicate things needlessly. I have since had T2 training.

 

[rjack321]

In my mind its not too bad to use a bottom stage to get 2 T1 dives out of a single set of doubles (e.g. on a charter). But you should have a few dozen T1 dives under your belt before doing this AND not have gotten lackadisical about your switches. I don't think you need any additional training to do this if you start breathing the stage on the surface. Likewise doing a 2nd shallower dive on a stage of 32%. I've done all of the above although I worked up to it over a couple yrs (not by design it just happened that way).

And I would say that at least my Cave2 bottom stage training is completely different from either of these applications.

OW deco dives needing a bottom stage as part of the total 1 dive gas plan are looking at 2 deco gasses too and that's alot of bottles without Tech2 (nevermind the 2 deco gasses)

Recreationally I would prefer people choose 2x big singles or bigger doubles way way before adding a stage. I.e. go simple.

 

[Vie]

In my mind its not too bad to use a bottom stage to get 2 T1 dives out of a single set of doubles (e.g. on a charter). But you should have a few dozen T1 dives under your belt before doing this AND not have gotten lackadisical about your switches. I don't think you need any additional training to do this if you start breathing the stage on the surface. Likewise doing a 2nd shallower dive on a stage of 32%. I've done all of the above although I worked up to it over a couple yrs (not by design it just happened that way).

Yes, your examples were exactly the situations where I would add a stage - although I (unwisely) did not "work up to" using a stage over a couple of years.