Buoyancy with 12cu Pony

[flyboy08]

i Dive warm waters, so I usually have no need to dive in anything more than shorts and a rash shirt...I’m diving with 14lbs...6 (3X2) in each pocket and a 2 in the rear trim pocket....I’ve been trying to get down to 12, but that’s still a work in progress.

I’m going to be diving with a new to me 13cu Pony as a stage bottle in a week.......probably should try the First Dive with 14lbs, but wondering what some of you more talented divers that have dove with the 13 might suggest or share what I might experience?

I plan to attach to my D rings in front of me....suggestions for fashion position are appreciated as well

 

[Schwob]

13cu Pony as a stage bottle

???
As in gas usage from that bottle is part of the dive plan?

 

[flyboy08]

???
As in gas usage from that bottle is part of the dive plan?

Yes....If I need to extend my Dive by 10 minutes or so to keep up with the wife’s consumption...80s don’t cut it and larger are not offered.

 

[rhwestfall]

other question aside, how are you rigging it? Of concern is that if your weighting utilizes it, what happens if you hand it off or for some strange/silly reason it is detached from you?

 

[flyboy08]

other question aside, how are you rigging it? Of concern is that if your weighting utilizes it, what happens if you hand it off or for some strange/silly reason it is detached from you?

Like to stay on topic of First issues First, but I don’t plan on handing it off.....it’s mine

Good Q though!

 

[rhwestfall]

Yes....If I need to extend my Dive by 10 minutes or so to keep up with the wife’s consumption...80s don’t cut it and larger are not offered.

so, you dive based on her air remaining.... what if she needs to share with you (and you consume much more)? This is a fundamental gas planning issue.....

 

[flyboy08]

Stage bottle...I don’t expect to run out of air...I surface with 500-750 psi usually....the wife with 1500. I would never allow air to be depleted to where a safe acsent and ST could not be completed....

 

[Fastmarc]

From Catalina, their 13cf is -1.8lbs full, -1.0lbs @ 500 psi and -0.9lbs empty.
High Pressure Aluminum Gas Cylinders | Composite Cylinders - Specifications Aluminum Cylinders | Composite Cylinders | Impact Extrusions
Other brands should be similar.

I recently started slinging a 19cf and had no need to adjust my weighting and my trim was not affected. However, mine is for redundancy and not a part of my gas plan.

 

[mi000ke]

there are a ton of threads on this board regarding why you should/shouldn't carry a pony, why you should/shouldn't sling it, why you should/shouldn't use it part of your dive plan, etc., etc.,etc., so no need to hash that stuff out here one more time.

Regarding weighting and buoyancy, which was your question, my 13 cf (Luxer) is -1.7 when full and -0.7 when empty. So not much of a weighting issue. I sling mine on the left. I typically dive with 2# in each chest strap pocket, and when I first started using the pony (I use it only on deep dives) I would eliminate the 2# weight from the left pocket for the deep/first dive. Then I went back to putting the 2# back into both pockets for all dives because I would forget to put it back in for the second dive. it made almost no difference either way.

 

[flyboy08]

I have a luxfer...stated weight for the 13 is 6 pounds. Salt water buoyancy -1.8 pounds full.......-08 empty.

If my scale is correct, with valve mine came in at 9 lbs!