Is there a valid reason for a pony bottle

[KenGordon]

Hi Ken,

Um, a, dunno! I am not side-mount trained...

I know a few side-mount divers and they tell me that an empty bottle on one side and a full one on the others side makes swim with a list. Would your thought cause balance problems?

markm

It would be full the whole time unless you had to use it. If that worries you then bleed off 70bar. You’d still have twice as much gas as you’d have if you took a 3l cylinder with you.

 

[markmud]

A pony is defined by its intended use, not by its size. Mine would typically be 40 cu.ft. as its buoyancy characteristics make it almost disappear underwater.

Hi grf88,

I have dived with a tank mounted 6cf, a slung 13 cf, and a slung 40cf. I really, really, really could not tell the difference. I did not change my sinker configuration at all because I did not need to.

I agree with you, and choose the pony size that fits the needs of your dive.

markm

 

[markmud]

It would be full the whole time unless you had to use it. If that worries you then bleed off 70bar. You’d still have twice as much gas as you’d have if you took a 3l cylinder with you.

Hi Ken,

No thanks. My ponies are well traveled and like flying. I will keep using my ponies.

markm

 

[KenGordon]

A pony is defined by its intended use, not by its size. Mine would typically be 40 cu.ft. as its buoyancy characteristics make it almost disappear underwater.

My criticism is that they are too small and introduce some extra risks. A 40 will be better size wise (twice the gas of a typical 3l) and so applicable to greater depths. Someone earlier was saying they had used as 13cf pony and it was twice the size of one they had previously used. Should there be a term for especially small cylinders which are useless deeper than 5m?

 

[KenGordon]

Hi grf88,

I have dived with a tank mounted 6cf, a slung 13 cf, and a slung 40cf. I really, really, really could not tell the difference. I did not change my sinker configuration at all because I did not need to.

I agree with you, and choose the pony size that fits the needs of your dive.

markm

So what dive suits a 6cuft ‘pony’?

 

[grf88]

My criticism is that they are too small and introduce some extra risks. A 40 will be better size wise (twice the gas of a typical 3l) and so applicable to greater depths. Someone earlier was saying they had used as 13cf pony and it was twice the size of one they had previously used. Should there be a term for especially small cylinders which are useless deeper than 5m?

Even a full 13 cu.ft. cylinder has a lot more air than an empty 130 cu.ft. cylinder.

 

[KenGordon]

Why do you care if I sling a pony since my pony won't be endangering you?

If you have a pony your incentive to be a good buddy is reduced. If you have a failure you don’t really care how far away he is. The mutually assured distruction contract is broken.

 

[KenGordon]

Even a full 13 cu.ft. cylinder has a lot more air than an empty 130 cu.ft. cylinder.

And drowning at 20m is different to drowning at 40m?

 

[saxman242]

So what dive suits a 6cuft ‘pony’?

I'll preface this by saying that I think a 6 cu ft pony is smaller than I'd personally ever carry, however, a 6 cu ft will support a diver with a .5 cu ft/min SAC rate at twice their normal breathing rate and a 30 ft/min ascent rate from about 70 feet, given that one skips a safety stop. It would probably be most useful in giving immediate air while switching to a buddy's octopus but it still sure as hell beats doing a CESA.

 

[grf88]

And drowning at 20m is different to drowning at 40m?

Typically you would not be using a 13 cu.ft. pony on a 40 meter dive but you could certainly do an assisted CESA with one if needed. I would not like to do a 40 meter CESA immediately after exhaling.