Pony bottle for BC & Octopus?

[92630Diver]

I have a question... being new to scuba I was wondering if it is acceptable to connect a pony bottle to a Scubapro Air 2 (or similar dual purpose BC inflator/octopus device) and thus use the air within the pony bottle for both buoyancy control and emergency air?

 

[scubabunny]

Don't think that is a good idea. What size pony bottle are you thinking of using? It might work, if the pony bottle was just attached to your inflator, but I wouldn't do it attached to the secondary air souce. Inflating and deflating the BC takes more air than you think, especially for new divers still fine-tuning their BC. The deeper you get, the more air it takes.

If you only use a pony for the BC and the second air sorce...what happens if you have an emergency, and you used all the air in the BC? Kind of scarey.

Pony bottles are meant to be a back up in case Murphey's Law decides to take control that day. Even for recreational diving, I don't think its a good idea.

 

[Rick Murchison]

One of the nice things about using a pony for a bailout bottle (safe second) is that in an air sharing event, you can hand the bottle off to the out of air diver and let them make their own ascent. If you attach the pony to your power inflator you're taking that option away (or at least making it a major pain).
Rick

 

[roakey]

If you're out of air you're aborting the dive. If you're aborting the dive, you're going up. If you're going up, you don't need to add air to your BC. Once at the surface you can orally inflate.

Never introduce a "solution" that's more complex than the original problem.

Roak

Ps. Notice the typical SCUBA gear progression that's happening: You’ve added complexity by adding a pony. Now you're adding complexity to that complexity. All to solve perceived problems that don't exist, or can be handled in a safer, simpler and more reliable manner.

Your brain keeps you from running out of air. In case of equipment failure, your buddy is your redundant air supply. Once the dive is called, you don't need to add air to your BC until you're at the surface (overhead excepted).

Simple, simple, simple.

 

[92630Diver]

Is adding a Scubapro Air 2 to the low pressure inflator hose of the BC increasing the complexity of the rig? I was under the impression that logically this simplified the configuration by removing one hose from the 1st stage and streamlining gear even further.

What has been relayed in regard to pony bottles is understood. My error was in not quite grasping exactly how much air volume is required to inflate a BC as relates to the volume of air compressed within the cylinder.

I was trying to deduce whether a 6 or 13 cu. ft. pony bottle would hold enough air to establish neutral buoyancy at depth and have sufficient reserve for an emergency accent with a buddy breathing off of the primary while I used the Scubapro Air 2. Or a similar scenario in which I ran out of air from the main cylinder and had to rely on the pony bottle.

The added risk factor apparently does not make this a practical configuration. Thanks for the input! I'll pass on obtaining a pony bottle but still plan on purchasing a Scubapro Air 2 for my BC.

 

[jetblast00]

Without having this discussion again in this thread, take at look at this recent thread
http://www.scubaboard.com/t6215/s.html
so see the reasons many people (including me) don't use pony's at all.

 

[Rick Murchison]

I use a pony for two different reasons.
Mostly, I use a pony as a deco bottle.
Occasionally I'll carry a pony along as an extra when I have a student whose self dicipline on air management is still suspect - not bad enough to deny him a chance to make the dive, but enough that I have that little itch about him.
I use a 30CF pony for these apps.
Rick

 

[scubabunny]

The Air2 is great (I'm sure some people wouldn't agree, but its a preference thing). It takes away one hose, and you always know where your octo is. Some instructors don't like it, but for recreational diving, it is wonderful!

Getting a pony bottle is still a good idea. It is an extra redundant air souce. If your buddy should run out of air, instead of sharing your tank, just unclip the pony and give it to him. Or, if you start running low unexpectedly (fight a current coming back to shore or boat) you can switch.

To learn the best way to carry a pony, you will have to ask the experts. I don't carry one yet, but plan on carrying one very soon...just to make myself feel better if nothing else!

 

[Rick Murchison]

Originally posted by scubabunny
The Air2 is great (I'm sure some people wouldn't agree, but its a preference thing). It takes away one hose, and you always know where your octo is. Some instructors don't like it, but for recreational diving, it is wonderful!

Getting a pony bottle is still a good idea. It is an extra redundant air souce. If your buddy should run out of air, instead of sharing your tank, just unclip the pony and give it to him. Or, if you start running low unexpectedly (fight a current coming back to shore or boat) you can switch.

To learn the best way to carry a pony, you will have to ask the experts. I don't carry one yet, but plan on carrying one very soon...just to make myself feel better if nothing else!

Using a pony as described and having an Air2 as well crosses the line of unnecessary complexity. You need *one* safe second. If you want to carry a bailout bottle by all means do so, but don't hook it to an Air2. To get redundant first stages and use an Air2 you should use either an "H" valve or doubles - something you don't intend to hand off.
If you're using a pony as a deco bottle, or carrying it acting as a safety diver then it isn't your safe second.
Rick

 

[fazlo]

I have been using SeaTec Original Mnata BC, Military version for the past 15 years, It came with a CO2 inflateor for emergency ascend. I had such a hairy experience one day that almost cost me my life because of this CO2 power inflateor. one of students panicked causing him to pull the cord and inflating my BC, luckily I was very close to the surface and no harm was done. The first thing I did was to remove this CO2 cartridge and plug the hole. If I need to do a rapid accent, I use my own power. I have been using Spare Air eversince. As for ScubaPro Air 2, I had nothing but trouble with it, freeflow, etc.... I have been using the Sherwood Shadow for about 10 years with no problems. As a Scuba instructor, I found ScubaPro Mark X, and a G250 to be the best Piece of equipment money can buy.