pony bottles

[Web Monkey]

Thats not what my buddy is there for!!!! Cold water, two breathing thru the same first stage, not a good idea!!!!

It's a great idea if you want to see if the regulator tech did a good job of packing the "anti-freeze" grease back into your first stage.

Terry

 

[Xanthro]

Believing one needs a pony bottle is inextricably linked to the concept of team diving. There are two ways to solve this problem...one is by adding gear, the other is by improving skills. One only requires money, the other requires time, energy, motivation, etc. When someone believes they need a pony bottle, often they don't address the real reason why: they aren't working together as a team. This is assuming that that individual believes in the buddy system in some way.

Team diving and redundant air are not mutually exclusive. You can have both.

It's impractical to use doubles in all diving situations. I've been on dive boats that don't allow doubles, dive boats that don't allow you to bring your own back gas. Sure, you could simply not do those dives, but many of us prefer to dive more often, and every dive is not an adventure.

Some of your examples are a bit extreme as well. 100 feet is deep. It's too deep to rely on even a 19cf pony. I consider 100 feet to be an extreme dive and I won't go past 60 unless I know for certain that my buddy is a great buddy and we have good team skills together.

If something goes wrong at 40 feet a 19cf pony is plenty. Sure, on these dives I could simply CESA if I had to, but I'd rather not. Taking a simple piece of gear is easier and safer, plus the cost is not lost. Most of the gear can be used on stage bottles later.

Great buddies make for the best diving, for reasons other than just safety, but having a redundant air supply doesn't mean you can't be in a great team.

 

[francousteau]

Believing one needs a pony bottle is inextricably linked to the concept of team diving. There are two ways to solve this problem...one is by adding gear, the other is by improving skills. One only requires money, the other requires time, energy, motivation, etc. When someone believes they need a pony bottle, often they don't address the real reason why: they aren't working together as a team. This is assuming that that individual believes in the buddy system in some way.

Perfectly said, Soggy! The only caveat is that here in NJ, if you want to go out on a charter and you're not diving doubles, then the captains are requiring a "pony". They really don't care how well you say you work as a team, etc. So, if the expense of twinning or some other reason is stopping someone from doubling and you want to dive some of our fantastic wrecks, then you have to get a "pony". Totally agree with everything you've said, but this is our reality in NJ. What I don't agree with is seeing a lot of new divers using 13cf'rs or 19cf'rs. Our wrecks are 60' - 130+ and never being sure which wreck you'll end up at, those small "pony's" are just not enough to get out of a jam. However, YMMV

 

[DandyDon]

In my opinion, use a pony bottle for the right reasons. As some have mentioned, go technical with a 40cf stage (Nitrox) for deco. Better yet, go with doubles.

Excuse me...?

I believe he was looking for good suggestions on bail-out bottles - to not be included on the gas use plan.

You are referencing something else...

 

[redacted]

Perfectly said, Soggy! The only caveat is that here in NJ, if you want to go out on a charter and you're not diving doubles, then the captains are requiring a "pony". .... . What I don't agree with is seeing a lot of new divers using 13cf'rs or 19cf'rs. Our wrecks are 60' - 130+ and never being sure which wreck you'll end up at, those small "pony's" are just not enough to get out of a jam. However, YMMV

What size "pony" is required by the captains.

What are your accident rate stats for divers with the smaller ponies as compared to those with the larger ponies? Or is the "just not enough" based on something else like limited options when a problem occurs? Is the statistical difference related to divers who returned to the boat versus diver who had to be recovered after being unable to return to the boat?

 

[francousteau]

What size "pony" is required by the captains.

AFAIK, there isn't a requirement on the "pony" size, only that you have one if you're not doubling.

What are your accident rate stats for divers with the smaller ponies as compared to those with the larger ponies? Or is the "just not enough" based on something else like limited options when a problem occurs? Is the statistical difference related to divers who returned to the boat versus diver who had to be recovered after being unable to return to the boat?

IMO, on page 7 @ 10:21am, Soggy already has answered the "just not enough" question.

 

[Jason B]

Excuse me...?

I believe he was looking for good suggestions on bail-out bottles - to not be included on the gas use plan.

You are referencing something else...

I think Soggy covered that already....

You just love 'pony bottle' threads don't you?

 

[DandyDon]

I think Soggy covered that already....

You just love 'pony bottle' threads don't you?

And since the poster missed it, I briefly pointed it out again.

You just love what you do, don't you?

 

[redacted]

So it can be said that I contributed *something* useful to this thread, let's do some math.

You just ran out of air on the bottom and your buddy disappeared into the ethos. You are (rightly so) somewhat freaked out about this occurrence. Your breathing rate skyrockets...probably at first to 1.5cft/min or more, but it will settle down once you have something to breathe. Let's assume a 1cft/min breathing rate from the bottom (at 100ft) to the surface, including a 30 ft/min ascent rate, and safety stop at 15 ft. The 1cft/min is reasonable considering that your breathing rate will spike initially and then slowly calm down to a somewhat normal rate.

Figure that you will need to spend a minute or so on the bottom dealing with the problem, and getting settled down. That's 4 ATA, so 4 cft in one minute.

Then, you start your 30 ft/min ascent. You will reach 15 ft in basically 3 minutes at an average depth of roughly 60 ft, or 3 ATA. That's 9 cft (3 ATA * 3 mins). We are up to 13 cft already, with a 13 cft tank, you just ran out of gas (for the second time) at 15 ft.

Now you are going to spend 3 minutes at 15 ft (1.5 ATA). That's another 4.5 cft, plus a 1 minute ascent to the surface...call that another 1.5 cft. Our total is 4 + 9 + 4.5 + 1.5, which is 19 cft. The 19cft tank will probably just squeek in as enough gas to make it from 100 ft with a 'normal' ascent. I would want more than what is the absolute minimum. When deco diving, we plan to carry 1.5x the 'required' amount of deco gas for the dive, just in case things don't go exactly as planned.

Obviously, I'm doing a bit of conservative rounding, but it's not unreasonably so.

Not that running out of gas at 15 ft is all that catestrophic an event.

But lets try another scenario. You are a solo diver and not dependent on a buddy. In spite of a good gas management plan and adequate monitering of your gas usage, some type of failure results in OOA and we can use the 100 ft of your problem. As any good solo diver wouold, you have a redundent gas source which you switch to immediately. You have prepared and equipped and practiced this sort of thing so your SAC basically remains at .5. (Or you can elevate it a bit but if you go to an unprepared, surprised, paniced then you are not talking about a prepared, self-relient solo diver) I'm going with an initial ascent rate of 60 FPM (wasn't that the safety standard for a long time?) so about 1 minute and a little less than 2cf later (or 4 cf if you really want to double the SAC if you have not been practicing enough) I'm at 40 ft and know that everything is under control. Might as well slow it down to 30 FPM so I should use another minute and 1 cf to get to the rest stop. I know I've got this incident under control and am wondering exactly where the boat will be and WTH went wrong (good thing I'm diving with the guy who serviced that reg). I take a look at my N load to decide if I want to go more than 3 min but I'm still 4 tics (of 12) away from the yellow (which I had been monitering even more closely than my SPG) and decide 3 is more than enough and I use about 2 cf (3 if you round up). Then the trip to the surface is about half a minute which we can call another 1 cf. Hell, I only used 6 cf - I got plenty left to inflate my wing and my sausage. And it packs nicely in my suitcase so it is not a problem when I travel.

 

[Soggy]

Or you could dive with enough bailout gas that you don't have to cut corners...either way....

You have prepared and equipped and practiced this sort of thing so your SAC basically remains at .5.

Monkeys could fly out of my butt, too. I thought we were talking about real life. You can practice whatever you want, but when you're down on the bottom and you draw that last breath, I assure you, you aren't going to be breathing a .5. I know *very* few people that breathe a .5 even when they are calm as can be, except in ridiculously warm water with ridiculous visibility. I spend a lot of time practicing OOG drills myself, but I guarantee if the time ever comes that I *need* to go up to my buddy after having drawn my last breath, my heart will be thumping a bit.

I'm going with an initial ascent rate of 60 FPM (wasn't that the safety standard for a long time?)

Yeah, until they knew better....just because you ran out of gas is no reason to blow your ascent plan. You might want to figure in a few cft extra to shoot a lift bag, too, so the boat doesn't run you over, or you don't drift out to sea.

But, feel free to cut your *BAILOUT GAS* that that close. I think that's borderline suicidal and completely idiotic. Hell, if you only need 5 cft, you should just get a manifolded spare-air or dive with one of those little 6cft argon bottles. Since you blew your plan so ridiculously that you are completely out of gas, and your buddy is gone, I'm sure you couldn't possibly have accumulated a deco obligation of any sort and your computer will always be "in the yellow", whatever that means.