should i dive with my ABLJ folded?

[cloudflint]

Hello everyone! I dive a buddy arctic ABLJ that "folds" away and fastens with poppers so you dont have any bulk, then when you inflate it the poppers burst and it all folds out.

I generally dive with it folded since it keeps it out the way and i never really have to use it while im diving. Anyway quite a few of the older members in my dive club are suggesting that I shouldn't dive with it folded since when the poppers burst they cause the buoyancy to drop, meaning that if you are being lifted you start going up then when the poppers burst the drop in buoyancy causes the lift to stall until more air is pumped in.

Anyway we chatted about it all evening and none of us could think of a reason why the poppers bursting would cause a drop in buoyancy though from experience they all agreed that in practice it seems to happen. So i was wondering if anyone had any ideas as to if the poppers bursting really does cause a drop in boyancy and if so why?

Im going to go jump in the river later and do some tests but its really bugging me thinking about it

 

[Nemrod]

WTH are you talking about mate?

N

 

[merxlin]

ABLJ = Adjustable Buoyancy Life Jacket = BCD

 

[cloudflint]

WTH are you talking about mate?

N

Not quite the reaction i was hoping for

Anyway here's a couple of pictures to show what i mean.

This is it folded up, there are poppers along the side that keep it all folded up:

And here it is unfolded:

 

[Nemrod]

I don't think that is correct, the volume displaced is the same, folded or not, the amount of water displacement by the injected air is also the same, folded or not, so the buoyancy should not change (for a given amount of air injected into the bladder) poppers undone or not. I am pretty sure about that but you can try and see for yourself that I am right.

BTW, yes, if it can fold to reduce bulk, by all means do so.

N

 

[Nemrod]

ABLJ = Adjustable Buoyancy Life Jacket = BCD

Well, see, a BC, buoyancy compensator, be it a jacket, vest or wing, is never a life jacket nor were any meant to be a life jacket and never have I seen one USCG rated Type I, II, II, IV so therefore the terminology, regardless, is incorrect. So therefore, my question, lol, WTH was he talking about with poppers and ABLJC or whatever it was or is or isn't.

N

 

[merxlin]

Well, see, a BC, buoyancy compensator, be it a jacket, vest or wing, is never a life jacket nor were any meant to be a life jacket and never have I seen one USCG rated Type I, II, II, IV so therefore the terminology, regardless, is incorrect. So therefore, my question, lol, WTH was he talking about with poppers and ABLJC or whatever it was or is or isn't.

N

Foreign translation

 

[cloudflint]

Foreign translation

Yeah ive discovered since joining this site that alot of the terminology seems to be completely different in certain countries Everyone I know calls the old horse collar jackets with the inflator bottles on them ABLJ's whereas ones that just have a direct inflator and no bottle we generally refer to as a horsecollar BCD

I must admit i said WTH too the first time someone talked about diving on a poodle jacket and an 80. I eventually figured out that what you would call an 80 we call a 12 and I think a poodle jacket is what we call a STAB jacket though im still not sure on that one

We refer to the ABLJ's as ABLJ's because over here im pretty sure they are classed as lifejackets for all intents and purposes, it may not have a USCG rating but that's understandable since i dont live in america

 

[John C. Ratliff]

Here's my take on this, which may be off because of terminology. When you say, "poppers," I'm thinking the overpressure relief valve and not the snaps that hold the jacket in a more compact form. If the snaps are in place, and you put the maximum amount of air into the BC, the overpressure relief valve may very well open before the snaps would let go. Therefore you would have less volume because the folding has reduced the amount of storage inside the BC. When you open up the BC, you would have more capasity because there were no folds, and the BC could get its maximum amount of air into it. Therefore, folded there would be less volume available, but it would be more streamlined.

So far as this being a "life vest," be aware that the very first BCs were actually Mae West life jackets, with CO2 inflators (I'm talking the 1960s here--this is a vintage site, right?). We called them a life vest because they would float an unconscious diver face up on the surface. These are still made and being used by rescue swimmers.

Cloudflint, how did your dive in the river go?

SeaRat

 

[Nemrod]

Yeah ive discovered since joining this site that alot of the terminology seems to be completely different in certain countries Everyone I know calls the old horse collar jackets with the inflator bottles on them ABLJ's whereas ones that just have a direct inflator and no bottle we generally refer to as a horsecollar BCD

I must admit i said WTH too the first time someone talked about diving on a poodle jacket and an 80. I eventually figured out that what you would call an 80 we call a 12 and I think a poodle jacket is what we call a STAB jacket though im still not sure on that one

We refer to the ABLJ's as ABLJ's because over here im pretty sure they are classed as lifejackets for all intents and purposes, it may not have a USCG rating but that's understandable since i dont live in america

That is funny, I was just messing with you.

I doubt your BC has a life preserver type rating in Britain either

Nem