Use of pony bottle

[scubasprout]

Our countywide dive team has been debating over our use of a pony bottle. We have been trained by LGS who advocates the use of removable pony bottle to pass off to a diver who may be entangled and then go back up to get a contingency bottle. We have several divers against the idea of "passing off" their only back up and want to use a hard bracket type of mount. This debate is really getting heated. Who else uses pony bottles and how do you mount or use them? Thanks for your input.

 

[ditch-diver]

We have pony bottles that are hard mounted in to the main tank. Our philosophy is the pony I have a is for me to use. We have it hosed in with an Octo for a completely redundant system as well as hosed through a Kirby Morgan block. We would never consider passing off the pony because it is for the diver. We do however setup a separate tank on site for the resuce diver to carry down to 'pass off' if required.

 

[Dive Junky]

 

[bridgediver]

99% of the time the back up diver is not going to have to go to the primary for an OOA problem - he will usually go to help solve an entanglement problem. This is the reason why he doesn't take the contingency bottle off the hop.
BUT, lets say he gets there and the primary IS having an OOA problem. He is on his pony because his main tank is empty and is entangled on the bottom (or can't immeadiately suface). The entanglement is not the problem it is air. If the back up can "pass off" his pony it will bridge the gap and give the primary another air source until the problem can be solved or more air (the contingency bottle) is brought down. Otherwise he will essentially be a solo diver with a single air source already in a precarious position. Should the back up risk that he will be back in time with the contingency bottle before the primary's pony is also empty? Quite a pucker factor if you're the primary!
Being able to remove the pony provides a lot more options for OOA situations.
If you can't pass it off you can't share it in PSD so the back up is pretty useless for an OOA problem if there is also an entanglement.

Bear in mind the only time you'd "pass" the pony is if the other diver has an empty main. If your mission is to help the primary (as it would be as a back up) who needs your pony more? You're headed right back to the surface to get another pony AND a contingency bottle so who's at greater risk?

 

[Indian Valley Scuba]

Hmmmm..aren't we ALL heading to the surface in any of these scenarios?

 

[scubasprout]

Here are some of the opositions brought up by some of our members...

If the tender and profiler are doing their job and know the diver's SAC rate and counting bubbles, they should be able to estimate how much air the diver has and know whether the contingency bottle should be brought down or not.

If the primary is entangled and the back-up passes his pony off to him to go back for the contingency, there is a good chance that the back up can also become entangled in the same obstacle and now he has no back up air supply.

Blades, what's your beliefs on this topic?

Thanks for the responses and please keep them coming. I would like to take all these to our next meeting to discuss.

 

[black1]

How about everyone having a pony, therefore if one is entangled, he can use his pony as well while others try to cut him away or go for help.

 

[bridgediver]

Hmmmm..aren't we ALL heading to the surface in any of these scenarios?

Most of the time, yes but if the diver is badly entangled it may take more time to free him than the pony bottle allows

 

[ditch-diver]

On our Supervisors Course..., they are trained that in any emergency the FIRST thing to ask the diver after finding out what the issue is..., "What is your depth and PSI?" The Sup then makes the call on whether or not to send the bottle.

There has been a little playing around with a coupling on the KM block to allow the safety to simply plug a new tank into the diver..., allowing him to keep his vision, comms and encapsulation but it is still at the 'just playing' stage. (Similar to what Interspiro has done with their new complete system that turns a diver from SCUBA to SSAD on the fly)

 

[bridgediver]

Here are some of the opositions brought up by some of our members...

If the tender and profiler are doing their job and know the diver's SAC rate and counting bubbles, they should be able to estimate how much air the diver has and know whether the contingency bottle should be brought down or not..

- If most of the time the problem is an entanglement the extra contingency bottle is just another thing the divers have to deal with. If its not needed don't bring it
- If the primary has 2 air sources all is well. Work to free him. If it takes a long time get the back up to bring the contingency bottle -- so far we don't have a need to pass any pony to anyone; we deal with the problem as easily as possible
Having said that if the tender gets a 3+3+3 and sees a large mass of continuous bubbles that looks like a free flow by all means bring down the extra bottle


I guess the problem IMO with calculating the need for the contingency is that it isn't for sure. You're not going to take it if you don't need it (because we rarely do actually need it) and things can change fast. having a pony that can be donated gives you the option of leaving the primary if you have to (ie get more air, tools etc). If the primary is OOA (empty main and little to nothing in the pony) and you can't pass him the pony you either stay with him and both drown or you leave him with no air (he drowns)

If the primary is entangled and the back-up passes his pony off to him to go back for the contingency, there is a good chance that the back up can also become entangled in the same obstacle and now he has no back up air supply.
.

Nothing is definate for sure. There's always a risk of entanglement but for the back up it is reduced quite a bit. Here's why
- he is approaching the primary from a different angle - mid water vs searching through the bottom where most of the obstacles are
- he is following the tether and not actively searching (arms/legs sweeping), turning etc.
- he is more alert to entanglements because thats probably why he is going and can be more diligent
- he shouldn't encouter any until he reaches the primary if the tether is tight as it should be. The line should be clear if the tender is doing his job - he would notice any snags as they occur and should stop the diver before they escalate.

These are common concerns - we've had these same discussions too and hopefully I'm describing things clearly enough for you. We should be able to address ALL the "what ifs" so that we can be assured that we can bring our divers home. We also want to deal with the problems as easily as possible - more task loading may make things worse but we also need to adapt as things change. A Q/R pony will give you another option

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