When would one choose Double AL80s over Double Steel 80s?

[ScubaInChicago]

Why do people not like dual bladder wings?


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Everyone knows your gonna die if you use one. Get the bungied type and go all out though.

 

[HungoverDiver]

as they used to say in the Bud Lite commercials: "Here We Go"......

Haha, I'm not trying to stir the pot. Just trying to learn. I've only used single bladder. I just don't know the difference.

Is everyone on scubaboard super touchy?! ;-)


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[TSandM]

Some topics are pretty reliably contentious.

A double bladder wing needs two inflators. If you keep both of them hooked up to LP hoses, then if one is auto-inflating, it's almost impossible to know which one it is to disconnect. If you keep the "backup" one disconnected, it can be difficult to get it hooked up if you are really plummeting and need it. Most things that would puncture a wing underwater will likely puncture two. And the whole need for double bladders can be avoided if you don't dive big, negative tanks with wetsuits.

 

[decompression]

Some topics are pretty reliably contentious.

A double bladder wing needs two inflators. If you keep both of them hooked up to LP hoses, then if one is auto-inflating, it's almost impossible to know which one it is to disconnect. If you keep the "backup" one disconnected, it can be difficult to get it hooked up if you are really plummeting and need it. Most things that would puncture a wing underwater will likely puncture two. And the whole need for double bladders can be avoided if you don't dive big, negative tanks with wetsuits.

Ditto![emoji2]


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[DivemasterDennis]

I agree that water temperature and exposure suit wonr are the most important factors. However, I have used double 80AL's exactly one time. A single AL 80 has always allowed me to complete maximum or very close to maximum NDL on every dive, except shallow dives and on those I always get to my PBL (personal bladder limit). Unless you are doing deco diving ( which you may be m ) or other technical diving, I do not get carrying an extra tank. Last November in Akumal MX we dove with a guy who used side mount with twin AL80's. The max depth of the 4 dives we did with him was 70 feet, and three of them were to a max of about 55. The longest dive was about 55 minutes. He was packing enough air to cover 3 dives like that ( or close to it). I guess I just don't get it.
DivemasterDennis

 

[TSandM]

Some of the most delightful diving I've ever done was diving double Al80's in the Red Sea. Some of our dives were fairly shallow, to be sure, but in my dry suit, with the Red Sea water temperatures, thermal tolerance was not going to limit my dives, and on the shallow ones, deco wasn't, either. So by having dual tanks, I could stay in the water as long as I wanted, which was not uncommonly 90 minutes or more. We also did some deep dives with some deco, and spending a half hour at our 20 foot stop wasn't bad, either.

 

[Kevrumbo]

Some topics are pretty reliably contentious.

A double bladder wing needs two inflators. If you keep both of them hooked up to LP hoses, then if one is auto-inflating, it's almost impossible to know which one it is to disconnect. If you keep the "backup" one disconnected, it can be difficult to get it hooked up if you are really plummeting and need it. Most things that would puncture a wing underwater will likely puncture two. And the whole need for double bladders can be avoided if you don't dive big, negative tanks with wetsuits.

All very real & non-specious arguments, but there are very skilled and competent divers and guides that I've met who understand and are prepared to handle these contingencies (bakodiver391 for instance, Dive Guide, Chamber Operator & Crewman on my Bikini Atoll Liveaboard Expedition 2013 on the M/V Windward).

I still prefer a back-up Liftbag rather than dual-bladder wing for the same reasons above --although a 40lbs Halcyon Wing barely kept my head above the surface swells pre-descent, with double AL80's and three AL80 single stage/deco tanks clipped-on (tropical 0.5 skinsuit with a 2mil hooded vest).

 

[TSandM]

For every topic on SB, there are people on both sides of every argument. I merely listed, because the poster asked, the arguments that are marshaled against double-bladder wings. I personally would prefer to configure my gear so that that particular bit of gear complication is not necessary. Other people make different decisions. My Razor has a double bladder.

 

[Kevrumbo]

For every topic on SB, there are people on both sides of every argument. I merely listed, because the poster asked, the arguments that are marshaled against double-bladder wings. I personally would prefer to configure my gear so that that particular bit of gear complication is not necessary. Other people make different decisions. My Razor has a double bladder.

Lynne you already understand there are "indications & contraindications" for every technique/procedure/treatment protocol and within every Specialty in Medicine --the same in technical doubles diving and even within overhead environments (i.e. Wreck vs Cave).

In this instance, the Bikini Atoll Dive Guide has to also bring up bail-out AL80 cylinders of CCR Divers as well, so he felt the use of a double-bladder wing was warranted despite the potential complexities/contingencies as noted. (I also decided to help out during that expedition and was carrying four clipped-off AL80's single stage/deco tanks in addition to my conventional double manifolded AL80's, but was trained to use a back-up/auxiliary Lift-bag in case of primary buoyancy wing failure).

 

[clownfishsydney]

If I used double steel tanks in the tropics, I would be so over-weighted I would swim at 45 degrees. I suspect that this is why most (every one I have seen) tropical location where you may need to use doubles for deep wrecks (eg Solomons, Chuuk, PNG, Vanuatu) only has aluminium.