Question about pony bottles

[scubadada]

I probably shouildn't even comment on this, as my views are different and irrelative ? to your question. Good job on not getting a Spare Air, many people go wrong there. Personally though, if looking at a reductant ? air source, I'd personally move on to sidemount or doubles, although the first option, which I highly recommend isn't possible for your son's age (15 yoa required for the course) and the second isn't in any way needed for your style of diving. Honestly, a reductant air source isn't needed based on what you have described. You aren't in an overhead environment, nor are you diving alone. Personally, I say continue to dive within your limits and as taught, save a reserve of air in case of an OOA or equipment failure situation. That is just my two cents though, and I am not familiar or have dived with anyone that has a pony (everyone around here just switches to sidemount if it comes to that)

Sidemount, the new BP&W?

 

[T.C.]

He's not wrong. The main drawback to solo is that redundancy comes from two tanks on one diver rather than two tanks on two divers; the main advantage is that for gas planning only one diver is breathing from either of those two tanks. Solo OC deep dives are a lot easier on gas planning than well planned team OC deep dives.

Why would you not want to carry as much gas as you can? If you run into a problem, there's only one person to solve it, and they'll need as much as they can get to return to the unlimited supply of breathing media.

Ask any Tanker. You can never have too much gas.

 

[dumpsterDiver]

Why would you not want to carry as much gas as you can? If you run into a problem, there's only one person to solve it, and they'll need as much as they can get to return to the unlimited supply of breathing media.

Ask any Tanker. You can never have too much gas.

Why not dive with 4 or 6 scuba tanks on every solo dive? You ask some strange questions. Take what you need and have fun. Do you fill the gas tank in your car at every gas station you drive by?

 

[NAM001]

I dont think you are missing a thing. My opinion is that it is ideal to have two seperate tanks. However costs bieng what they are and making the confirurations as simple to rig use and swicth to as possible for OW level divers training leads to the methods involving a single tank. I would have both a primary and a secondary reg on your primary tank and a seperate primary only on the pony w/ valve shut off. Keep in mind that you are venturing into the grey area of the rec tech boundries adnthat those you are diving with meay not know how to deal with your set up when trained otherwise in OW class. Also if you are not set up to properly to carry and use a pony then it may be useless and serve as not much more than ditchable weight.

My son (14 years old) and I are relatively new to diving, 3 years and about 40 dives, over half are salt water boat. Our max depth is about 80 ft, diving with steel 100 singles. Both of us are AOW with nitrox certification.

My question is about pony bottles. I just bought 19 cf bottles for each of us. I am going to rig with primary off the tank, and octo off the pony. I've review our previous dive sac rates, and 19 cf should be more than adequate for the diving we do.

It seems to me only logical that carrying your own back up air would be far superior to depending entirely upon a buddy in an OOA/equipment failure situation.

And my question... Since it SEEMS a no brainer that a pony is superior to a single tank with octo, am I missing something???

 

[scubadada]

YES! Pony bottles have literally KILLED people. It is important that you understand how.

But first, i will tell you I always dive with a pony and so does my young son. It is an essential part of our configuration and there is absolutely no way i could enjoy my dive or turn my back on my son (who started diving with me at 9 yrs old) if he was not wearing a redundant system. I would just be way too nervous.

The pony you bought is over-kill for 80 ft depths.. my son uses a 6 cu-ft to depths of 90 feet or so.

But back to how a pony can kill you or your son... IF (and only if) you back mount the tank like I do.... there is a potential to confuse the two second stages - mixxing up the pony versus main tank... So this is how the accident can evolve..

The diver checks his air in both tanks, checks the regs for operation, turns both tanks on and gets ready to dive. Some silly distraction occurs, maybe the diver is sea sick and pukes and feels terrible and just wants to get below the waves..

So after the puke fest, the diver grabs the pony reg, and rolls over. Now 8.36 minutes later it gets a little hard to breath and then there is one more breath and nothing. The diver checks his has supply (from the primary tank) and the gage shows full, but he ain't getting no air from the regulator (when a pony goes empty, it is much faster than a big tank- you can't milk it slowly) ---

So the diver figures his main tank must have somehow failed and he is getting a little panicked and confused, so he spits the regulator out, maybe signals to his buddy who isn't watching at that precise moment and then... he tries to switch regs, but since he is absolutely sure he was breathing from the primary reg, he puts the empty pony bottle reg BACK in his mouth and gets nothing.

He is beyond panic, can't understand why BOTH tanks failed today and since he has been dicking around instead of heading for the surface during this whole ordeal, he may well die if he doesn't get air from his buddy. People HAVE died with empty ponies and full working tanks and I personally know an inexperienced diver who made this exact mistake on a solo dive and just barely figured out his mistake.

A pony bottle does add some complexity. It is safer to have it clipped off in the front like a stage bottle, but that is a PITA, particularly if you don't have BC's that provide good attachment locations. if the tank is clipped off in front of you like a stage bottle and you can SEE the tank and follow the hose and regulator, it is almost impossible to get confused. But, I use back mounted... less safe, more prone to entanglement and more confusing during a failure (still the benefits outweigh the drawbacks for me).

This video shows an actual scuba failure i had with my son while diving with a pony bottle. We (I) got my signals crossed and ended up with some confusion of where the failure was from my back mounted rig. We weren't close to a really dangerous situation, but it might give you some insight into some issues.

You can skip forward to about 1:45 minutes if you get bored. FYI. this video is authentic and not staged in any manner.


[video=youtube_share;Bap2PxetarQ]http://youtu.be/Bap2PxetarQ[/video]

---------- Post added May 19th, 2014 at 07:37 PM ----------



There are some very good reasons to NOT carry 3 second stages. Particularly if you back mount the pony. The potential for freeflow and failure goes up significantly. During a free flow event, it may be very confusing as to which reg is actually the problem.. a new rec diver is going to be stressed enough with a simple free flow, juggling three regs can add to the confusion. Also a second stage clipped off in the golden triangle is quite likely to freeflow and on a hard descent down an anchor line in a strong current when you are enveloped in the bubble stream from 2-3 divers (working hard) below you and it is EASY to fail to detect your own freeflow..

The diver needs to balance the increased complexity, potential for failure versus the added safety and/or convenience of each piece of gear. It is NOT a no-brainer to carry 3 second stages with a typical back mounnted pony configuration.

I sling my pony, it can't free flow without me seeing it, I can't confuse the 2nd stage with any other, the SPG on a short hose let's me know exactly what I have, I could always pass it off if I wanted to.

 

[T.C.]

Why not dive with 4 or 6 scuba tanks on every solo dive? You ask some strange questions. Take what you need and have fun.

By your "logic", you only need a little 63 cu ft tank and a Spare Air. That's all you'll "need", and it will get it to the surface (if you don't breath hard on it), right?

At some point, you draw a line and don't take 4 tanks, but you're saying to take less of the one critical supply that will keep you alive in the tanks you do take. It does not make sense.

Do you fill the gas tank in your car at every gas station you drive by?

Yes, if I'm going to be the only vehicle around, have a reasonable expectation that no one will come to save me in time if I do run out, and don't know the conditions or problems that may occur before I can arrive at the next station.

Have you ever driven remote areas in winter? That's essentially what you're doing when solo. If you run into a problem, you can't call for AAA, and no one will come by to get you for a very long time. If you don't have food, water, a heat source and/or enough gas, you are in serious trouble.

But you'd be advocating taking your convertible with the top down, and calculating that you can drive at peak efficiency to the next station. No worries about sliding off into the ditch and being stuck for a week and running out of fuel- you've got one of those dinky 1.5 gallon gas cans in the trunk. You'll be fine...

 

[Dr. Lecter]

Why would you not want to carry as much gas as you can? If you run into a problem, there's only one person to solve it, and they'll need as much as they can get to return to the unlimited supply of breathing media.

Ask any Tanker. You can never have too much gas.

As someone who used to dive double 130s, I tend to agree. That said, there's no ing good reason to take that mantra to extremes, or you'd be diving a CCR with a ton of bailout on 30' rec dives. If you have a choice between lugging a 130 and a pony and an 80 and a pony, and the 80 gives you enough reserve...take the 80.

Or take the 130, if you don't care about the weight and might take off deeper; I usually do when I don't want the hassle of CCR for a couple rec/light deco dives off a rec boat. But a post wailing about the wrongness of 'hey, solo halves your gas planning so you can at least consider a smaller main tank'? Yeah, that's over the top.

 

[T.C.]

As someone who used to dive double 130s, I tend to agree. That said, there's no ing good reason to take that mantra to extremes, or you'd be diving a CCR with a ton of bailout on 30' rec dives. If you have a choice between lugging a 130 and a pony and an 80 and a pony, and the 80 gives you enough reserve...take the 80.

I'd still want the 130. Can I get a "cave fill" on it too?

I can see two tanks, but I'd still want as much as I can carry.

Besides; doubled 130s? What is that, 125 lbs or so? Tooo Easy.

 

[Akimbo]

...Ask any Tanker. You can never have too much gas.

Are you sure about that?

 

[Dr. Lecter]

I'd still want the 130. Can I get a "cave fill" on it too?

I can see two tanks, but I'd still want as much as I can carry.

Besides; doubled 130s? What is that, 125 lbs or so? Tooo Easy.

Closer to 140lbs, counting the 16lbs of air (more if you whack em up to 4000 and change). Don't forget the BP, regs, can light, wing, etc. Everyone talks about how heavy and negative the rEvo is, I just give thanks I'm not wrangling steel doubles anymore