kubefish
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i usually wind up diving solo. i have decided to purchase a second air source. i have not decided if i should get a pony bottle or a spare air. any suggestions?
Spare Air or Pony?
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o2diver
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Go with the pony bottle, it allows you more oppertunities to change gear configuration and amount of spare air you have. It also allows you to use the bottle for deco gas.
large_diver
Contributor
Kube,
In the recent issue of Alert Diver magazine (published by DAN in the US), there is an interesting article on redundant air sources, including SpareAir and pony bottles. It discusses the advantages and disadvatages of each and also provides useful data on the amount of air consumed on a typical ascent from different depths (using a few ascent rates, I believe). It also compares this usage data to the amount of air available from different sizes of ponies, SpareAir, etc.
It is a useful article, allowing you to evaluate the type of diving you do and what would work best for you.
Hope this helps.
In the recent issue of Alert Diver magazine (published by DAN in the US), there is an interesting article on redundant air sources, including SpareAir and pony bottles. It discusses the advantages and disadvatages of each and also provides useful data on the amount of air consumed on a typical ascent from different depths (using a few ascent rates, I believe). It also compares this usage data to the amount of air available from different sizes of ponies, SpareAir, etc.
It is a useful article, allowing you to evaluate the type of diving you do and what would work best for you.
Hope this helps.
large_diver
Contributor
Kube,
1 more comment -- I know there are several shops in my area (Boston) that will rent you pony bottles. May be worth seeing if you can rent one for a couple dives to help you with your choice. My local shops rents them for something like $10/day.
-LD
1 more comment -- I know there are several shops in my area (Boston) that will rent you pony bottles. May be worth seeing if you can rent one for a couple dives to help you with your choice. My local shops rents them for something like $10/day.
-LD
This question has come up a couple of times here (you might want to do a search) I have been thinking about this issue as well and from what I see there is one acpect that seems to be overlooked but to me is just about as important. That is, will you actually carry it along. A pony with it's reg adds a good bit of weight and special handling is necessary to carry it on a plane. Spare Air and similar systems certainly don't give you the air reserve of even a 6 cf pony but a pony at home gives you even less. You will no doubt see a post or 2 calling them "spare death" or the like. I think this is a bit short sighted. Given the option of a spare air or nothing, I will take the SA. Would I depend on a spare air for a 100+ ft wreck dive? ^%$#@#@!!!!! NO!! Would I use one on a 40' reef dive instead of trying to carry a pony/reg on an airplane, yep. Given the choice of a 40' reef dive that I could drive my car to...pony for sure. For me I guess it boils down to what kind of diving am I doing and will I actually carry it along... looks like I need both. By the way, the DAN article is pretty good.
Herman,
When it comes to taking it on a plane, the same regulations apply to a spare air as do to a pony. Airlines don't like either.
you regularly hear of people getting away with a spair air in their dive bag, I have flown several times with my pony in my dive bag no problem, but I have always been prepared to leave it behind if the airline find it.
Just .02
Jon T
When it comes to taking it on a plane, the same regulations apply to a spare air as do to a pony. Airlines don't like either.
you regularly hear of people getting away with a spair air in their dive bag, I have flown several times with my pony in my dive bag no problem, but I have always been prepared to leave it behind if the airline find it.
Just .02
Jon T
True but a spare air weighs a lot less than a pony and my gear already weighs in at over 45lbs ( I usally get "heavy" tags placed on my luggage)and takes up a lot less space which all goes back to my main point that if it becomes a big pain to carry, you likely won't. All I need is 25lbs more in my jam packed luggage. Actually, that's an interesting question, just what is the difference in weight of a SA and say a 13cf pony w/reg. I don't see a 6cf pony is much better than a 3cf SA and if I need a pony then I don't see using less than a 13cf.
Don Murray
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About 5 years back I tested my Spare Air on a 60' to 15' ascent. It had about 3 breaths left. Can't remember the ascent rate, but it was probably too fast by todays standards. I did stop at 15' for that reason. They are better than nothing. My personal emergency plan is to start up or to another diver at the first sign of any air supply problem. Try the alternate reg. If nothing is available soon, then take out the Spare Air and ascend as slow as I think the depth will allow. If deeper than 60' then there may be some consequences. I consider this a life saving procedure. If you want to be sure there are no consequences at greater depths, then a Spare Air is not adequate.
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Hi kubefish,
Here's a little orientation I put together on emergency air supply. Hopefully you'll find it informative:
"Cylinders providing extra air for emergency situations come in three forms: The small bailout bottle, pony bottle (a large bailout bottle) and independent twin tanks.
Small bailout bottles, like Spare Air, that typically attach to the BC, come in sizes from a tiny 1.2CF to Spare Air's 6CF "600-Twin." Attached to the main cylinder by bands of various sorts, pony sizes range from 6CF up to 50CF, although with the latter it probably would be safer & more cost-effective simply to set up standard size independent twins.
Which set up is best for you depends on your typical dive plans. For example, for dive plans in shallower water, say above 60 feet, the largest small bailout bottle may just barely suffice. With deeper recreational diving, a pony bottle would be better. When technical diving is planned, such as depths exceeding the recreational, overhead environments, and where there are known entanglement hazards, independent twins are often wisest.
Spare Air advertises 30 surface breaths for the 1.7CF unit, 57 for the 3CF & 144 for the twin 3CF set up. More useful, however, are estimates of emergency gas needs while actually diving. Depending on breathing rate, to ascend from 60' at a brisk 60FPM without a safety stop requires anywhere from about 2 to 7CF air. From 100', it's from about 3CF to over 12CF. For a slower ascent and 15' safety stop for 3", you'll need proportionately more gas. It of course would be prudent to base your calculations on the increased consumption rates expected in an emergency situation.
As you can see, 3CF of air won't get you far. For this reason, it is important that a diver carrying a small bail out bottle not be lulled into a false sense of security. Once in trouble, he will have scant no time to solve problems or even make himself positively buoyant. At best, the diver will have enough gas to make an emergency ascent and reduce the risk of AGE because he's breathing off of something.
Other things you'll want to consider are the logistics of transporting & rigging various systems. Larger capacity emergency air cylinders typically mean greater size & weight, and while small bail out bottles are connected to the BC via velcro straps, holsters or lanyards, ponies are attached by bands and doubles require a special BC. Finally, while bail out bottles are small & minimally affect buoyancy, ponies & doubles impact buoyancy, trim & drag, and compensation needs to be made. It is important to consider inconvenience & nuisance factors as whatever your system, if you don't take it diving it can't assist you.
Cost is always a consideration, and none these systems are cheap. Since you asked about Spare Air, they offer 3 rigs. The MSRP for the 3CF is nearly $300, 3CF nitrox is about $330 & the twin 3CF closely approaches $500. Pony and independent doubles set ups can run in this same range depending quality of components, but can easily be assembled for well less than the price of the Spare Air twin 3CF unit. Be aware that whatever set up you decide on, the cylinders, regs & and associated pieces need the customary inspections & servicing. If you go with the Spare Air, I'd suggest ordering the optional dial pressure gauge, or supplying your own bolt gauge, to replace the standard pop-up stick model.
Regarding fills, bail out bottles usually are filled from the diver's main cylinder, although they can be compressor filled. Most divers carrying ponies, except for the smallest sizes typically prefer to have these compressor filled rather than off their standard tank.
As final note, remember that the systems discussed here are nothing more than emergency gas sources, and are not to be thought of as ways of extending dive times. The diver still is required to properly monitor his main air supply, and follow whatever buddy plans have been established prior to the dive."
Happy shopping.
DocVikingo
Here's a little orientation I put together on emergency air supply. Hopefully you'll find it informative:
"Cylinders providing extra air for emergency situations come in three forms: The small bailout bottle, pony bottle (a large bailout bottle) and independent twin tanks.
Small bailout bottles, like Spare Air, that typically attach to the BC, come in sizes from a tiny 1.2CF to Spare Air's 6CF "600-Twin." Attached to the main cylinder by bands of various sorts, pony sizes range from 6CF up to 50CF, although with the latter it probably would be safer & more cost-effective simply to set up standard size independent twins.
Which set up is best for you depends on your typical dive plans. For example, for dive plans in shallower water, say above 60 feet, the largest small bailout bottle may just barely suffice. With deeper recreational diving, a pony bottle would be better. When technical diving is planned, such as depths exceeding the recreational, overhead environments, and where there are known entanglement hazards, independent twins are often wisest.
Spare Air advertises 30 surface breaths for the 1.7CF unit, 57 for the 3CF & 144 for the twin 3CF set up. More useful, however, are estimates of emergency gas needs while actually diving. Depending on breathing rate, to ascend from 60' at a brisk 60FPM without a safety stop requires anywhere from about 2 to 7CF air. From 100', it's from about 3CF to over 12CF. For a slower ascent and 15' safety stop for 3", you'll need proportionately more gas. It of course would be prudent to base your calculations on the increased consumption rates expected in an emergency situation.
As you can see, 3CF of air won't get you far. For this reason, it is important that a diver carrying a small bail out bottle not be lulled into a false sense of security. Once in trouble, he will have scant no time to solve problems or even make himself positively buoyant. At best, the diver will have enough gas to make an emergency ascent and reduce the risk of AGE because he's breathing off of something.
Other things you'll want to consider are the logistics of transporting & rigging various systems. Larger capacity emergency air cylinders typically mean greater size & weight, and while small bail out bottles are connected to the BC via velcro straps, holsters or lanyards, ponies are attached by bands and doubles require a special BC. Finally, while bail out bottles are small & minimally affect buoyancy, ponies & doubles impact buoyancy, trim & drag, and compensation needs to be made. It is important to consider inconvenience & nuisance factors as whatever your system, if you don't take it diving it can't assist you.
Cost is always a consideration, and none these systems are cheap. Since you asked about Spare Air, they offer 3 rigs. The MSRP for the 3CF is nearly $300, 3CF nitrox is about $330 & the twin 3CF closely approaches $500. Pony and independent doubles set ups can run in this same range depending quality of components, but can easily be assembled for well less than the price of the Spare Air twin 3CF unit. Be aware that whatever set up you decide on, the cylinders, regs & and associated pieces need the customary inspections & servicing. If you go with the Spare Air, I'd suggest ordering the optional dial pressure gauge, or supplying your own bolt gauge, to replace the standard pop-up stick model.
Regarding fills, bail out bottles usually are filled from the diver's main cylinder, although they can be compressor filled. Most divers carrying ponies, except for the smallest sizes typically prefer to have these compressor filled rather than off their standard tank.
As final note, remember that the systems discussed here are nothing more than emergency gas sources, and are not to be thought of as ways of extending dive times. The diver still is required to properly monitor his main air supply, and follow whatever buddy plans have been established prior to the dive."
Happy shopping.
DocVikingo
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