Is there a valid reason for a pony bottle

[barth]

Isn't swapping tanks a bit of a chore compared to swapping a single? Or do you bring two full rigs?

That's the main reason I prefer a single tank rig. I don't have a compressor on my boat, and stowing a spare single tank is a lot easier than stowing an extra twinset.

If you have 2 complete sets of doubles it can be done in 5 minutes. Remove regulators, remove wingnuts, remove wing and backplate, remove v-weight, place v-weight at other set of doubles, place wing and backplate, tighten wingnuts and tighten regulators.

This is how the boat looks with extra sets of doubles and stages (Northsea).

There is enough time at the Northsea if you have to wait for the tide... Only when there are big waves you should be careful. And it is not a good idea if all the divers change their sets of doubles at the same time.

 

[scubadada]

Sorry I've been following the thread but have lost track of the question. Of course, there is a role for a pony. You dive solo, you need a redundant source to ascend from your deepest depth. The calculation is very simple assuming you know your RMV

 

[Storker]

Remove regulators, remove wingnuts, remove wing and backplate, remove v-weight, place v-weight at other set of doubles, place wing and backplate, tighten wingnuts and tighten regulators.

A bit more faff than swapping a single, then. Thanks for the info.

 

[dead dog]

Hi tursiops,

I never thought of a spare air as a viable option. I can't do sheet on 1.5 or 3cf.

Is your spare air still in hydro and vis? Why would you assume spare air, was it a statement against self-interest?

Spare air is death-in-a-can, that we can agree on.

thanks,
markm

Would you call that spare tire in the trunk of your car Death in the Trunk?

 

[grf88]

Would you call that spare tire in the trunk of your car Death in the Trunk?

If it wasn't fit for the task in hand yes!

 

[Nigel Bryant]

Can anyone give a valid reason for a pony bottle? SO many things need to be wrong before it makes any sense to me.

Only one thing needs to go wrong before it makes sense. The seal between your cylinder and first stage fails and you are now out of air. No pony and a errant buddy and you are in a world of pain. With a pony you are not. I dive with a pony and have used it once when my buddy had this happen to him. After using my octopus I then gave him my pony regulator and we carried out an ascent quite easily. I appreciate we could have achieved the same on my octopus but the redundant supply means I dive a lot happier.

 

[dead dog]

If it wasn't fit for the task in hand yes!

A pony bottle is fit for the task. Redundant air.

When I started diving in the 50's we depended on the J Valve (reserve) valve which was 300psi later it was increased to 500psi. We learned quickly that the valve could be tripped to the on position by accident. In my case, it was a fisherman's net that was draped over a wreck, that caught my tank valve in the net. I untangled my valve from the net by taking off my tanks off and swam out of the wreck with my tanks under my arm handed off my camera and put back on my tanks, then I was out of air. Lucky for me there were other divers on the wreck and I flagged one with the out of air sign. Next day I went to the Surplus (Pally's) Store and bought a small fire extinguisher to be made into a pony bottle. Once I had that I never ran out of air again. I called it my good luck bottle. Yes, I believe in pony tanks.

What do you say about an Octo Regulator? Is that Death next to your Tank?

If any of you don't like pony bottles then don't use one. But, don't knock those of us that do use the pony bottle.

 

[grf88]

A pony bottle is fit for the task. Redundant air.

When I started diving in the 50's we depended on the J Valve (reserve) valve which was 300psi later it was increased to 500psi. We learned quickly that the valve could be tripped to the on position by accident. In my case, it was a fisherman's net that was draped over a wreck, that caught my tank valve in the net, and I was out of air. I untangled my valve from the net by taking off my tanks and swam out of the wreck with my tanks under my arm handed off my camera and put back on my tanks, then I was out of air. Lucky for me there were other divers on the wreck and I flagged one with the out of air sign. Next day I went to the Surplus (Pally's) Store and bought a small fire extinguisher to be made into a pony bottle. Once I had that I never ran out of air again. I called it my good luck bottle. Yes, I believe in pony tanks.

What do you say about an Octo Regulator? Is that Death next to your Tank?

If any of you don't like pony bottles then don't use one. But, don't knock those of us that do use the pony bottle.

A Spare Air is a trade name for a tiny bottle which I believe holds about 1.5 cu.ft. of air and is basically useless as a pony bottle and what I believe was being referred to in the post you responded to. If you read my posts you will see I am an enthusiastic promoter of the use of an appropriate pony.

 

[MaxBottomtime]

A pony bottle is fit for the task. Redundant air.

When I started diving in the 50's we depended on the J Valve (reserve) valve which was 300psi later it was increased to 500psi. We learned quickly that the valve could be tripped to the on position by accident. In my case, it was a fisherman's net that was draped over a wreck, that caught my tank valve in the net. I untangled my valve from the net by taking off my tanks off and swam out of the wreck with my tanks under my arm handed off my camera and put back on my tanks, then I was out of air. Lucky for me there were other divers on the wreck and I flagged one with the out of air sign. Next day I went to the Surplus (Pally's) Store and bought a small fire extinguisher to be made into a pony bottle. Once I had that I never ran out of air again. I called it my good luck bottle. Yes, I believe in pony tanks.

What do you say about an Octo Regulator? Is that Death next to your Tank?

If any of you don't like pony bottles then don't use one. But, don't knock those of us that do use the pony bottle.

A situation like that could now be avoided by having and monitoring an spg.

 

[Gareth J]

A situation like that could now be avoided by having and monitoring an spg.

Contents gauges where not readily available during the J valve era. Thats why they had J valves.
J valves remained popular for poor visibility diving (commercial diving).
The 'false' activation of J valves was a well known weakness. The result - a frantic swim for the surface.
The other issue was the 'activating arm' sometimes came free from the valve.

If you look at the older diving books, there is a signal for J valve failed to operate. Although I guess out of air would also be valid.

A lot of the commercial boys used to carry pony's for exactly that reason. Some are still required to carry them on surface supply, it gives them a chance to get back to the bell if they loose surface supply.