Pony vs larger tank?

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OldNSalty

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I am thinking about redundancy and such and have considered getting a pony bottle. I went into a LDS and was looking at some new gear and asked about it. Well the guy doesn't have pony bottles in stock (not at the size I was looking for) and told me I should just buy a larger tank.

Here was his thinking (besides selling what he had in stock); If your reg malfunctions then it will have to break in the open position and you have free flow. He then asked the obvious 'You do know you can still breath on a free flowing reg don't you?'

OK, I get his point but I still don't think it is as best as having a completely seperate setup but I wanted to hear back from people who may know better then me.

Just the FYI part as it may be important. I currently dive Al80's, warm water only (gulf coast of the USA or further south) with a typical dive between 40ish and 80ish feet. I was thinking a small 13 would be enough to get me from max bottom of 80 to surface with a short safety stop.

I am not sure I buy the bigger tank theory (moving up to a 100) as I am not sure how quickly the air could escape. If I am at the end of my dive and something goes wrong would I still have enough air to make a safety stop?

Thoughts?
 
I am looking at the XTR air setup advertised on XS Scuba website (XS Scuba Product Guide) I mentioned this to two local dive shops I frequent and received very welcomed assistance, information and suggestions on size (13 vs.19 etc.), regs/octo to consider, pressure gauges to consider etc. Both did not suggest to purchase new tanks. I would go with a redundant air setup like the XTR air and build your own according to your $$$$ limitations. I was advised a pony bottle will not go that far, especially at 80'. As far a breathing from a free flow tank, I posed the question several months ago on this site and was directed to a video on you tube which was very cool. Bottom line is that there is not much time on a free flow. Another thing to consider is if you are diving alone or with a buddy. If you are in trouble with a pony bottle, the only direction your going is up but with a 19 or larger, you may have time to work yourself out of a pickle and do a short stop etc. Just my 3 cents.
 
I am thinking about redundancy and such and have considered getting a pony bottle. I went into a LDS and was looking at some new gear and asked about it. Well the guy doesn't have pony bottles in stock (not at the size I was looking for) and told me I should just buy a larger tank.

Here was his thinking (besides selling what he had in stock); If your reg malfunctions then it will have to break in the open position and you have free flow. He then asked the obvious 'You do know you can still breath on a free flowing reg don't you?'

OK, I get his point but I still don't think it is as best as having a completely seperate setup but I wanted to hear back from people who may know better then me.
If you think about this a little more, you'll arrive at the correct answer on your own. :D
A larger tank is not a redundant gas supply. Period.
Just the FYI part as it may be important. I currently dive Al80's, warm water only (gulf coast of the USA or further south) with a typical dive between 40ish and 80ish feet. I was thinking a small 13 would be enough to get me from max bottom of 80 to surface with a short safety stop.
Lamont has a nice webpage that explains the concept of Rock Bottom. Check it out.
NWGratefulDiver also has a succinct explanation on his personal website.
Feel free to do your own calculations.
I am not sure I buy the bigger tank theory (moving up to a 100) as I am not sure how quickly the air could escape. If I am at the end of my dive and something goes wrong would I still have enough air to make a safety stop?
Air can escape very quickly through a low pressure hose. The scenario you cite is a strong argument for having a backup gas supply -- whether that is a dive buddy or a pony bottle is your decision to make. That being said, there are other reasons to purchase a 100 cuft tank. I prefer the buoyancy characteristics and added capacity of my HP100 relative to the typical AL80.
 
Hey I dont know about you but I live in Naples Florida and on my dives I always use a 19cf pony that i sling across my chest. I know it will get me to the surface safely with my safety stops. IMHO diving in the gulf sometimes becomes solo diving just because of the vis.
 
Thanks guys, that was kind of what I was thinking. I may/will (in time) buy a larger tank but not 'instead of' a pony.
 
Hi OldNSalty,

Just more food for thought: You may want to consider an Al30 rather than an Al19. The reason is that the physical size and weight difference between the two tanks is negligible, the 30 only costs slightly more (check prices online to confirm this for yourself), and it holds almost double the air.

Best wishes.
 
well I would suggest an al40, but you have to have your harness setup to sling it off your (usually left) side. but any size would be better than nothing. Its important to have enough air/ nitrox in your bottle to be able to bring you up and allow you to do your stops. if slung you have to be able to take it off your harness to be able to hand it back up into the boat, so practice is a good idea. I believe that all divers should have a pony stage setup of some kind when diving deeper than 60ft. I know its expensive to do so.
 
The pony will give the redunancy you seek. Seperate gas and reg. An H valve will give you a redundant reg. Just something to consider. forget about freeflow John
See you topside!
 
I am thinking about redundancy and such and have considered getting a pony bottle. I went into a LDS and was looking at some new gear and asked about it. Well the guy doesn't have pony bottles in stock (not at the size I was looking for) and told me I should just buy a larger tank.

Here was his thinking (besides selling what he had in stock); If your reg malfunctions then it will have to break in the open position and you have free flow. He then asked the obvious 'You do know you can still breath on a free flowing reg don't you?'

OK, I get his point but I still don't think it is as best as having a completely seperate setup but I wanted to hear back from people who may know better then me.

Just the FYI part as it may be important. I currently dive Al80's, warm water only (gulf coast of the USA or further south) with a typical dive between 40ish and 80ish feet. I was thinking a small 13 would be enough to get me from max bottom of 80 to surface with a short safety stop.

I am not sure I buy the bigger tank theory (moving up to a 100) as I am not sure how quickly the air could escape. If I am at the end of my dive and something goes wrong would I still have enough air to make a safety stop?

Thoughts?


I don't dive without a redundant system, and usually now that means doubles but thats another thread.

I own an aluminum 19 which I backmount for any dives in "good" conditions and shallower than say 60ft (depending on conditions)

I own an aluminum 40 which I sling for any dives in "poorer" conditions or deeper than 60ish feet (depending on conditions)

T
 
If I am at the end of my dive and something goes wrong would I still have enough air to make a safety stop?

Thoughts?
If you are at the end of the dive you would be shallow and could just surface on the remaining air in your tank during a free flow. Unless you don't look at your spg, you should have enough air for you and a buddy to surface at any point in a dive.
A safety stop is a recommendation to get divers to slow their ascents. It is not a required stop. In an emergency you would not make a safety stop.
 

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