Just bought a pony system, need help with answers...

[Scubaroo]

Karl_in_Calif once bubbled...


I never said HE was safe diving to 185 ft with his brand new pony.

In nontechnical PADI diving, you may very well stop all conversations at 130 ft, which of itself is probably 30 feet more than is probably safe. I cannot speak for PADI's tec-rec protocols. Since you are PADI diver, ScubaRoo, you are most certainly coming from their perspective, whatever it is.

I doubt anyone would be safe diving to 185' with a single tank and pony bottle - but if you're happy to do it, go for it. I would doubt any divers choosing to dive those depths with a single tank are people I would choose to be my buddy.

I'm not coming from any agency's perspective. Just my perspective.

 

[MechDiver]

Scubaroo once bubbled...
I doubt anyone would be safe diving to 185' with a single tank and pony bottle - but if you're happy to do it, go for it. I would doubt any divers choosing to dive those depths with a single tank are people I would choose to be my buddy.

I'm not coming from any agency's perspective. Just my perspective.

Excellent statement. That deep on a single tank is not only stupid, its a waste of time.

MD

 

[IzzyTahil]

rakjar - keep in mind that a pony is only for redundancy and emergencies. a pony should give you enough air to bring you up from depth, thats why do not get a small bottle!! I sling my 30cf bottle now. Used to have it backmounted but find that I prefer this setup since I have a small button gauge that i can see an monitor the air. I made the sling for about 5 bucks.

 

[MikeS]

Karl_in_Calif once bubbled...
My own general calulations for ponies give the following, regarding size:

6 cu ft pony is good to 45 ft

13 cu ft pony is good to 115 ft

20 cu ft pony is good to 165 ft

30 cu ft pony is good to 185 ft

Karl,

Out of curiosity what is the basis for your “general calculations?” For example, what depth, surface air consumption rate, assent rate(s), safety stop? Do they allow any time at depth to sort out a problem or must you ascend directly to the surface? Does this include sufficient air for you or both you and your buddy?

I think that dispensing advice like this without making the limitations clear is dangerous.

Mike

 

[Karl_in_Calif]

MikeS once bubbled...


Karl,

Out of curiosity what is the basis for your “general calculations?” For example, what depth, surface air consumption rate, assent rate(s), safety stop?
Mike

RMV 0.75

Ascent rates:

from 185 ft --100 ft = 100 ft / min
from 100 ft -- 60 ft = 60 ft / min
from 60 ft -- 20 ft = 30 ft / min
from 20 ft -- 0 ft = full final usage of tank/bottle

Single deep stop at 1/2 max depth of 1 min

Final stop at 20 ft for 3 mins


I have also often heard the [fallacious] argument that "you need more time to sort things out" etc. In reality, when you switch to your pony, for whatever reason, its time to make like a hockey team and move the puck out of there.

fal·la·cious [ fə láyshəss ]

adjective

1. containing mistaken belief: containing or involving a mistaken belief or idea

2. deceptive: deceptive or liable to mislead people

[Early 16th century. Via Old French fallacieux from Latin fallaciosus , from fallacia (see fallacy).]

fal·la·cious·ly adverb
fal·la·cious·ness noun

 

[MikeS]

rakjar once bubbled...
1. Now that I am using my octo for the pony system, would anyone advise also getting a safe second for my SeaQuest ProQD BC?

Don’t use the “octo” second stage for the pony system. Adding a separate first and second stage regulator to the pony setup is the conventional method.

rakjar once bubbled...
2. Does anyone advise the use of a guage with the pony system? I have heard both yes and doesn't matter. Which one, yes or no?

I think a SPG is appropriate on a pony system for the same reason it is on your primary system; so you know how much gas you have left. The amount of gas remaining should influence your course of action. For example, should you head directly to the surface or do you have sufficient gas remaining for a safety stop?

A pony is not a good substitute for good gas management! The reason that I carry a pony on deeper dives is in case of equipment failure (i.e. burst hose). If you do decide to get a pony make sure you understand the capacity in terms of time at depth, required ascent rate, safety stop, etc. And just as importantly practice with it before you need it which is hopefully never.

Mike

 

[MechDiver]

Karl_in_Calif once bubbled...


RMV 0.75

Ascent rates:

from 185 ft --100 ft = 100 ft / min

The 60'/min from that depth is bad enough, but 100'/min

Please don't anyone believe, let alone do this hogwash.

I don't know what to say. This is beyond the pale.

MD

 

[Karl_in_Calif]

MikeS once bubbled...

I think that dispensing advice like this without making the limitations clear is dangerous.

Mike

If you want to hang a mill stone around him, and scare him into hauling a 30 or 20 cu ft pony now, you are doing him a disservice.

6 cu ft or 13 cu ft is more than enough, especially for now.

I use my 6 cu ft pony for really shallow night dives.

I use my 13 cu ft pony for dives to 100 ft max.

If I am going deeper than 100 ft, I bring a stage bottle with EANx in it.

The main issue for our relatively new diver, who has now seen the light about an alternate air source for himself, is size. He really should not dive deeper than 60 ft anyway, until after his AOW class.

If everyone dived with a pony bottle, and knew how to properly deploy them, there would be less scuba fatalities in the world. Probably half.

 

[Karl_in_Calif]

MechDiver once bubbled...


The 60'/min from that depth is bad enough, but 100'/min

Please don't anyone believe, let alone do this hogwash.

I don't know what to say. This is beyond the pale.

MD

Actually those are standard current TDI protocols.

 

[Karl_in_Calif]

MikeS once bubbled...

A pony is not a good substitute for good gas management! The reason that I carry a pony on deeper dives is in case of equipment failure (i.e. burst hose). If you do decide to get a pony make sure you understand the capacity in terms of time at depth, required ascent rate, safety stop, etc. And just as importantly practice with it before you need it which is hopefully never.

Mike

Exactly right!