Pony bottles VS stage bottles

[DeepBound]

By that standard, manifolded doubles are also still a SINGLE gas source. All it would take is for an isolator o-ring to go and you're hooped.

I dive with a stage as my redundant gas source, and have been thinking about going to doubles. Since the isolator o-ring is a single point of failure, is it common for solo divers to use double tanks with no manifold at all? To do that, would you switch back and forth from one regulator to the other to maintain balance?

 

[cuberoot3i]

i try to dive my plan. this will tellme what i should take. if i'm off shore not doing a deco, i might hang a stage in 30 ft for back up.

 

[Rick Murchison]

What would you classify a 30cf bottle slung on D-rings? Pony or stage? Is the difference the size or where you carry it?

It's a 13cf pony bottle slung like a stage.
This way I can keep the valve off until needed, and it won't lose it's air. Also it can be handed off to someone and it's less trouble than setting up the tank attachment each time.

I refer to a 30 as a pony, because it is small. If it is used as a redundant supply I call it a bailout bottle, if it is used to extend the range of the dive, a stage. If it is filled with deco gas, I call it a deco bottle.
As a practical matter I don't use ponies as stages, only as bailouts or decos.
Rick

 

[PvilleStang]

Well, I prefer using a set of doubles with an ISOLATOR manifold, with captured O-rings. If one blows, isolate, and you'd still have most your gas in the other tank, and a way back to the surface. The odds of blowing a single captured O-ring is very low, but to blow both, well, God just wants you in Heaven that day! And if its that bad, I'll sling a 40 on the D-rings and have at it. But my point here is, the Isolator manifold does serve its purpose, and if your diving a manifold valve with a cap on it, you're at just as much risk of an O-ring blowout, same with an H-valve. On that note, where's the Y valve divers? Those seem to be better than the H valve, since there are less failure points, but I've managed to see very few of those out there in comparasion to the H valve...

 

[abman]

i always dive with either a pony bottle, when i'm diving with a single tank or if i'm diving my doubles with a manifold and isolator valve with double regs. either system i'm always diving with a redundant setup. i usuaually dive with din valves as this is just one more saftey factor with the captured o-rings. ken