pony bottles

[NJScubaDoc]

Ok, so if you've got a team and all operate on the same wavelength then sure, yes, you would be correct. I, however, am not that lucky and depending on the buddy d'jour I like to think that in a worst case scenario they'd be there for me, but if not I have peace of mind knowing I've got extra air regardless.

 

[mnj1233]

I have been thinking about getting a redundant system for diving. I am think about the 13cf or the 19cf. I would strap these to my main tank. Any input would be helpful. Also if anyone has the knowledge.... about how much time can one get from these pony bottles. I know it depends on the person but a close guess would help.
Thanks in advance for your help..

This is the original post LOL Dont think teams/DIR etc. was ever mentioned.

 

[Soggy]

Ok, so if you've got a team and all operate on the same wavelength then sure, yes, you would be correct. I, however, am not that lucky...

Honestly, it's not a matter of luck, it's a matter of investing the time and energy into developing a group of divers into a team. It doesn't work if you don't believe in the system, or half-*** it.

 

[Soggy]

This is the original post LOL Dont think teams/DIR etc. was ever mentioned.

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.

For those that have made educated decisions and chosen to solo dive...sure, I guess a pony bottle could work. It's not the *best* solution from an equipment standpoint (that would be manifolded doubles), but it is *a* solution. Mounting it on your back isn't a great idea since it creates line traps, can be difficult to reach the valve, can't see leaks, etc, etc, but if you are going to solo dive or same-ocean buddy dive and you are diving in conditions that make doubles completely impractical, a pony is better than nothing. However, 13 cft is an argon, in my opinion, not redundancy. Consider you are panicked, at 100 ft, and need to ascend and do your safety stop...I've done the math before, but at an elevated breathing rate of 1 scft/min, you need basically 16 cft of gas just to get yourself to the surface....32 cft if you plan on diving with a buddy. I'd just get a 40 cfter...at least it can get turned into something useful later on - a deco bottle.

And no one mentioned DIR. Team != DIR. If I were to draw a venn diagram, DIR would be a circle inside of team.

 

[mnj1233]

I could start a thread titled "Mask: Blue, Yellow or Clear Skirt" and the same explosion diving theory would emerge. The thread starter asked two simple questions: 13 or 19cf? and how to mount it??? You tell me again this thread did not go astray.

 

[Soggy]

I could start a thread titled "Mask: Blue, Yellow or Clear Skirt" and the same explosion diving theory would emerge. The thread starter asked two simple questions: 13 or 19cf? and how to mount it??? You tell me again this thread did not go astray.

It went on a tangent, but not astray. Frequently people post here asking what they think is a simple question, but in reality they are asking the wrong questions. 13 or 19 cft? The answer is neither. If you "need" a pony bottle, you "need" something with a more useful volume.

 

[scubaren]

I bought a 30 pony bottle after being told that divers "run out of air on a regular basis". That scared me into it. The person who told me that dives very often and it sounds to me like there are many incompetent divers out there. The regular folks I dive with NEVER run out of air. As I've said before I am new to diving and am not able to tell at the surface who has their act together. I'd rather be safe than sorry.

 

[mnj1233]

It went on a tangent, but not astray. Frequently people post here asking what they think is a simple question, but in reality they are asking the wrong questions. 13 or 19 cft? The answer is neither. If you "need" a pony bottle, you "need" something with a more useful volume.

Fair enuf!!!! No hard feelings eh.

 

[Soggy]

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.

 

[Soggy]

Fair enuf!!!! No hard feelings eh.

No hard feelings. We are all just talking. Trust me, I've gotten in plenty of online 'battles' with people and usually and when we actually meet, we find out that we're all just regular guys that just want to dive. Some of those people, I wouldn't choose to dive with, but I would certainly have a drink with. The Internet blows everything out of proportion because people infer tone and inflection where there is none.