Deco stage set up

[Garf]

Originally Posted by DAFFY

well then Claire I suppose BSAC (bearing in mind I have only done the BSAC ad/nitrox course so cannot compare to other agencies) who suggest in the manual an inverted and primed cylinder as a possible kit configuration must be wrong then

it IS a possible configuration. Just not a very good one.

[NotDeadYet]

Originally Posted by Clare Gledhill

I would appreciate confirmation whether an agency suggests anywhere in their literature that three cylinders, one single and two ponies both backmounted, is a *good* configuration. Some agencys and instructors have to be able to work with whatever config the student turns up in - it is not the same as recommending it.

IIRC IANTD used to use a slide in one of the manuals of Richard Pyle's trimix rig which he used for fish collecting before he started RB diving. It was (if I can remember it):

- large single cylinder of trimix
- pony of trimix
- large single of nitrox with h-valve
- pony of O2

All backmounted.

[Colin Marriott]

All this debate just shows a clear case of why ALL divers should dive their cylinders the proper way round, with the valves easily in reach at waist height, and stop this stupidity of preaching that they should be behind your neck, out of reach, and if you can't reach them, then you're crap diver. . .







ColinM

[STE@DY]

IVE JUST STARTED ON TWIN 12S AND A 7L STAGE AND IM STILL TRYING TO FIND A SET UP THAT I GET ON WITH HAVE FUN

[Steve S]

Hi videogirl,

everyone has an opinion based on their experiences and or agency, DIR advocates tend to have the same one

I would go on the course and let your instructor show you, and let you try different configurations and tell you of their pros and cons, I did my BSAC advanced nitrox with a 15lt and 3lt backmounted pony, the same year I did my IANTD advanced nitrox with independent twin 10's and a stage rigged 3lt, I did my ERD with inverted twin 12's and a 7lt stage.

I was lucky that none of my instructors had closed minds.

With the faceless media that is the internet it's easy to make a 'wrong for you' decision based on another's experience, so my advice is to make your mind up as to what configuration is best for you when you have tried as many setups has you can.

Safe diving,
Steve

[chrisch]

Originally Posted by Steve S

...I did my BSAC advanced nitrox with a 15lt and 3lt backmounted pony, the same year I did my IANTD advanced nitrox with independent twin 10's and a stage rigged 3lt, I did my ERD with inverted twin 12's and a 7lt stage. ...

I think looking at the OP's profile (ScotSAC SD) this progression is going to be something like sensible. Use the current pony rig for the gas switching (I am assuming that ScotSAC, like BSAC does not allow accelerated deco? Someone put me right please)

Move onto accelerated deco later and move onto twins at that time.

By using a pony mixture with a MOD that does not exceed the dive depth at 1.6ATA you can still use it as an emergency redundant gas source. (ie 30m dive: air backgas EAN40 or less in the pony)

Again if you are doing actual decompression dives of more than a minute or two deco, a single 12 is inadequate backgas and a 3L bailout/pony is inadequate safety so the current setup is academic, you will be diving twins.

Chris

[SilvaFish]

I've just been to GD at lunch today and bought a 7l Ali stage.

the fun will start tomorrow...

[Mal Bridgeman]

Originally Posted by Steve S

I was lucky that none of my instructors had closed minds.

Having a closed mind is not the same thing as having a standardised system which has been optimised over many thousands of diving hours which I am sure you are aware. A dogma is different to being able to understand the rationale of a design choice and then testing it in water.

Some students tip up to courses with closed minds and miss out too you know

Unfortunately, too many people are getting hurt, diving systems/configs/procedures they have designed/developed themselves.

Mal

[NotDeadYet]

Originally Posted by chrisch

I think looking at the OP's profile (ScotSAC SD) this progression is going to be something like sensible. Use the current pony rig for the gas switching (I am assuming that ScotSAC, like BSAC does not allow accelerated deco? Someone put me right please)

Move onto accelerated deco later and move onto twins at that time.

By using a pony mixture with a MOD that does not exceed the dive depth at 1.6ATA you can still use it as an emergency redundant gas source. (ie 30m dive: air backgas EAN40 or less in the pony)

Again if you are doing actual decompression dives of more than a minute or two deco, a single 12 is inadequate backgas and a 3L bailout/pony is inadequate safety so the current setup is academic, you will be diving twins.

Chris

About the most sensible post yet!

Originally Posted by Mal Bridgeman

Having a closed mind is not the same thing as having a standardised system which has been optimised over many thousands of diving hours which I am sure you are aware. A dogma is different to being able to understand the rationale of a design choice and then testing it in water.

Some students tip up to courses with closed minds and miss out too you know

Unfortunately, too many people are getting hurt, diving systems/configs/procedures they have designed/developed themselves.

Mal

People do chop and change and dive all sorts of rigs but if you look at people who have been doing twinset/deco diving for a number of years, the vast majority have invariably set their kit up very similarly in the end, whether DIR or not. There are superficial differences (which most arguments start over) but generally everything ends up similar (if not the same). I remember a lot of people diving quad-rigs in the late 90's... strangely I don't know any who still are.

Having an open mind is great but the sport has been around long enough that what works tends to be how most people end up doing it.

Cheers,

Stuart

[Steve S]

Originally Posted by Mal Bridgeman

1) Having a closed mind is not the same thing as having a standardised system which has been optimised over many thousands of diving hours which I am sure you are aware. A dogma is different to being able to understand the rationale of a design choice and then testing it in water.

Some students tip up to courses with closed minds and miss out too you know

2) Unfortunately, too many people are getting hurt, diving systems/configs/procedures they have designed/developed themselves.

Mal

1)It is if that prevents the instructor from advising on a configuration that may be the best option for that particular students needs, one size doesn't fit all tha' knows.

2) I'll take your word on that, but I would suggest that the vast majority of divers are lucky enough to survive a kit choice that may be sub-optimal then move on to something that better suits their needs, without having to move to the darkside for a safety cloak

Safe diving,
Steve