Need opinions on LDS purchase

[SM Diver]

I just bought a 6 cf pony tank at LDS. I notice date of manufacturer is 1997. It is on display as a new item. I ask if it was preowned, and they said no. However, they now have to send it out for testing, so I can't pick it up until Thursday. I went ahead and paid full price ($113). Was this stupid of me? I got to thinking, full price for a tank that is now 5 years old. They said they've had it a while. Since it's not preowned, is it good as new?

 

[redacted]

But surely not worth new price. Leisure pro has it for $75.00. Plus 6 cu ft is rather marginal on gas supply. And that supply will dwindle rather quickly in pre-dive checks and the occasional freeflow. Can you back out of this one and go for something a bit larger?

 

[MikeFerrara]

hmm...

Not sure about a 6 cu ft but a 14 cu ft cost me (a dealer) the same as an 80 (about $110 before shipping). So to me the price seems good. I couldn't sell one for that. The Leisure pro price of $75 is way way less than I can get it for. The fact that it's out of hydro doesn't hurt anything as long as they're not making you pay for it.

 

[WreckWriter]

Good for an argon bottle but not much else.

Tom

 

[SM Diver]

So, not only should I not have paid full price, but, basically, a 6 cf is worthless anyway. I normally don't dive redundant air, but will be down 100 ft this weekend. I also have a 13 and 19. I guess I'll use at least the 13. It would seem that would be enough air to get to the surface in an emergency.

But if 6cf is not worth much, why do they sell so many spare airs? I figured by doubling the 3cf in a spare air, I could easily make it to the surface without adding a lot of additional weight.

 

[redacted]

In terms of gas supply, 6 cu ft is roughly equivilant to about 230 psi from your Al 80. It should get you to the surface comfortably but very short if any rest stop. Bump it up to the 13 cu ft, which is only slightly heavier and larger with all the same overhead of a regulator and carrying system, and you get the full rest stop. The spare air should also get you to the surface with a bit less overhead, but you'll have to hurry - maybe a lot.

 

[sheck33]

tampascott once bubbled...
So, not only should I not have paid full price, but, basically, a 6 cf is worthless anyway. I normally don't dive redundant air, but will be down 100 ft this weekend. I also have a 13 and 19. I guess I'll use at least the 13. It would seem that would be enough air to get to the surface in an emergency.

But if 6cf is not worth much, why do they sell so many spare airs? I figured by doubling the 3cf in a spare air, I could easily make it to the surface without adding a lot of additional weight.

Yes, a 6 cft is not very useful for anything other than an argon bottle. Your buddy is your redundant air supply. You say a 13cft tank 'would seem' enough to get to the surface, personally if i were to use a pony bottle, which i dont, i would want to KNOW whether 13 cft is enough to get me AND my buddy to the surface.

the fact that airmanagement is not taught in PADI courses and only in more advanced TDI courses rather than in the OW course is beyond me. WHy dont you find out what your SAC rate is and calculate how much you would need to get you and your buddy to the surface from a 100'? That will be an enlightening calculation

they sell al lot of spare deaths because new divers dont know any better and most LDS will sell anything to a new diver regardless of whether he/she actually needs it or not.

dont waste your money on pony bottles, if you think you need a pony bottle you should be diving doubles

 

[raviepoo]

tampascott once bubbled...
I normally don't dive redundant air, but will be down 100 ft this weekend.

What is your gas consumption like? How long do you plan to stay at 100 feet? Will you be breathing air or Nitrox?

I don't use a redundant air supply in warm water. I just plan my dive to leave enough gas for the ascent.

I think the tiny boost you would get out of a 6 cubic foot tank is probably not worth the hassle of having to deal with the tank. Don't use up all of your air on the bottom and be sure you dive with a buddy who has an octopus and knows how to use it.

 

[JimC]

Just to walk the exercice, for kicks. The comments about training don't aplly to many people, but are based on typical OW training provided these days.

WHy dont you find out what your SAC rate is and calculate how much you would need to get you and your buddy to the surface from a 100'?

Assumptions:
Depth: 130fsw (5 abs atm)
"Stressed" SAC: 1 cf / min
Accent profile: 30f/min, 3 min @ 15fsw

Calculations:
Accent Time: 7.3 min
Av Depth: 45fsw
Gas Used: 10cf

Add your buddy to that, and a 19cf pony is going to be pushing it. Most people are going to end up with more than 1cf/min SAC stressed, especialy if they do not practice or are new. Sure its lots of air if your calm and have SAC rates under 0.5cf/min. Most people don't. Now run the above, and have something else go wrong... like say, spending 2 minutes at depth getting controll of the situation, recovering your lost mask then finding the accent line (since your OW training didn't include free acents or any reasonable boyancy controll).

Spare air? Perhaps if you carry 6 of them across your chest comando style.

 

[redacted]

I got my pony primarily for solo diving but frequently carry it on buddy dives. In that case, I figured that the 500psi I'm planning on taking to the rest stop belongs to my buddy if he needs it, but the pony is mine (or buddy's if that is the regulator that he grabs). I've never really thought about sharing the air in my pony. I've never seen one rigged with 2 seconds to facilitate such sharing. If you are going to size the bottle for 2 wouldn't it make sense to rig it for 2 also? OK, there is always buddy breathing, but planning on that seems to be just asking for trouble.