Anybody come across this thing yet? All in one pony bottle.

[NYCNaiad]

Regarding my earlier post about slinging a 13 cf pony:

Context: All my dives have been and will be non-solo recreational boat dives in warm, high visibility, low current Caribbean waters where we are usually doing an underwater loop that never goes very far from the boat, plus the occasional shore dive out to a reef and back. My max depth is generally about 100’ as I am almost always on EAN32 and I give myself a few feet of safety factor. My normal SAC rate is about .45 cf/min. I can (have done) CESA from about 50’ if needed. I have two herniated discs/sciatica and want/need to minimize the amount of weight I carry out of water. (Btw, diving is incredibly therapeutic for my back.) I have never seen anyone else on one of my dives carry a pony, but it gives me a little peace of mind.

Calculation:
At 100’ for one minute to get sorted out: .45 x 4 x 1 = 1.8 cf
Ascend from 100’ (4 atm) to 15’ (1.5 atm) at 30 fpm  2.75 ave atm x .45 cf/min x 85’/30 fpm = 3.5 cf
Safety stop at 15 ‘ (1.5 atm) for 3 minutes: 1.5 atm x .45 cf/min x 3 min = 2 cf
Ascend to surface: 1.25 ave atm x .45 cf/min x 15’/30 fpm = .3 cf
Total air consumption: 7.6 cf

If I speed up my ascent to, say, 45 fpm then we are talking 6.3 cf
If I eliminate the safety stop we are talking 4.3 cf

I am comfortable that a 13 cf will do the job for me if for some reason I become OOA. Plus I don’t want to carry the extra 3 lb of a 19 cf.

I'm guessing you probably haven't been in a situation where you panicked or were out of air. My air consumption is very good & I also have the same back problems you do. Your air consumption will change DRASTICALLY in an emergency situation. Mine did which is why the larger pony generally makes more sense. In good conditions, I have the boat hand me down my gear when I'm in the water & I hand it up before I get in. This way, I don't have to worry about the weight at all.

 

[The Chairman]

I'm guessing you probably haven't been in a situation where you panicked

Most people believe themselves immune to panic because it's so irrational. That is, until they panic. Most people believe that their air consumption will increase only slightly if they actually did panic. That is until, like you found out, they panic.

Denial: Not just another river in Egypt.

 

[ScubaSteve85]

It's an interesting point. I figure if I'm having to use my emergency gas supply then a bottom swim is out of the question. In my mind if I switch, I expect to be moving vertically almost immediately. From my perspective even one of those puny 3cuft spare air tanks might be enough. Maybe not, but I'm highly confident that 13 will get the job done with gas to spare..

I want it to be small enough that it won't be a hassle. If it becomes a hassle, I'll end up leaving it at home where it won't do anyone but the LDS who sold it any good. I know myself and I know if it is a hassle it won't go anywhere.

Exactly what I'm thinking. I know it's always better to have more than you need of something, especially when were talking about air, something quite important to us mammals, however, in my mind, a 13 or definitely a 19 would give me enough time either get to my buddy, who should be right there, or perform a more or less emergency ascent, with whatever safety stop I can manage. It's important to understand I'm talking about recreational dives only. Wreck diving, dives over 120+ ft, etc, obviously justify special consideration and considerably more planning for any potential eventuality.

 

[JohnN]

Most people believe themselves immune to panic because it's so irrational. That is, until they panic. Most people believe that their air consumption will increase only slightly if they actually did panic. That is until, like you found out, they panic.

Denial: Not just another river in Egypt.

Like Mike Tyson said: Everyone has a plan until they get punched in the mouth

 

[mi000ke]

If you HAVE to switch to your pony, how confident are you that your SAC is going to still be at 0.45?

Well I expect my SAC will go up, but I guess I don't expect it to go up 5x (with all due respect to netdoc). I practice using my pony bottle regularly, and as the pony reg is sitting almost in my hand, it's just matter of switching regs. Not a big deal. I am NOT talking about saving myself from some catastrophic event like a heart attack, a shark attack, or getting caught on something (all pretty low probability given the dives I do), just possible equipment failure that consumes my air. I check my air obsessively when diving. I am almost always among the last to come up on the guided dives I do, so there are at least a few others checking air as well who consume faster than I do. I do not expect to be surprised by a OOA situation under normal conditions. And if my SAC doubles I still probably will have enough air, at least to get to where I can CESA. And if not, I'll drown. Such is life, such is diving. There are worse ways to go. I'm OK with the risk of having only 13 cf. And it's 13 cf more than every other diver I have dived with so far (I have never dived with anyone else who carried redundant air.). If I'm at risk, what about them?

 

[dhaines429]

I have a 13 cf and a 30 cf. I use the 13 when I am diving with other experienced dives who are also carrying redundant air as it is then just in case i have a situation with free flowing reg or other gas problem. I sling the 30 when out with less experienced divers as I can hand it over to the out of air diver and put myself at less risk.

 

[Kharon]

If you're going to sling a bottle, an AL40 is just as easy as a 19 or a 30.

Not if you are 70 and walking into/out of the water on Bonaire in swells.

Run out of air and watch it jump to 4 or 5 times normal. That 4.3 to 6.3 just became 21.5 to 31.5 cf if you can't get your breathing under control.

Point is - don't run out of air!!! That's not what my pony is for. It's for the unexpected (relatively speaking). With well maintained equipment (I do my own) and situational awareness the chance of the unexpected (for me - no one else) becomes vanishingly small. And I don't need to think about my buddy needing air. I dive solo.

... Your air consumption will change DRASTICALLY in an emergency situation. Mine did ...

Why is it that everyone assumes that everyone else will react the same way that they do? As a matter of fact I have been caught up in several seriously life threatening situations - much more serious than an OOA situation. My reaction has always been 1. a calm "SHITE, I could die here" 2. "OK, what do I do now". I have never panicked in my life - so, no, my air consumption will not change drastically.

 

[The Chairman]

I have never panicked in my life - so, no, my air consumption will not change drastically.

You remind me of the guy who claims he never gets narced. It's not that I don't trust you, or think you're a dangerous diver due to your denial. I'm just not the type of buddy you need or want. I would be embarrassed to be always in your shadow, so I'll find a more er, mortal buddy. It's not you, it's me. Rly, rly. I'm sure you'll find a far better buddy than me. I just wouldn't be able to measure up. Have fun.

Not if you are 70 and walking into/out of the water on Bonaire in swells.

Been there. Going back. Always carry a bailout when I dive my rebreather. OK, I'm only 60.

Why is it that everyone assumes that everyone else will react the same way that they do?

I have never run out of air since I started using an SPG. I wish I had sprung for one far, far earlier in my diving career. I don't carry a bail out on rec dives, but if I did it would be a 40. Why? Simply because I have had to deal with others running out of air. Unless you're diving solo and away from all other divers, you never know when you're going to asked for air. If you give it, then you have no control over their breathing.

 

[Kharon]

... I'm just not the type of buddy you need or want. ... I'm sure you'll find a far better buddy than me.

I guess you missed the point completely - I don't want a buddy of your type, better than you, far better than you - I don't want a buddy ever. My buddy is my pony.

 

[2airishuman]

If you're going to sling a bottle, an AL40 is just as easy as a 19 or a 30. I have the other two and I'll break them out for a diver's first attempt slinging a bottle, but I have a lot of 40s and I can use one dive after dive after dive.

The main difference is weight while topside and particularly when entering or exiting the water.

If you happen to have lots of 40s, great, they work for you, but not everyone is in that situation.

Run out of air and watch it jump to 4 or 5 times normal. That 4.3 to 6.3 just became 21.5 to 31.5 cf if you can't get your breathing under control..

I don't think it's plausible to assume it will jump to 4x-5x and then remain there for the entire ascent.