Proper Weighting w/ Pony Bottle

[Aquanautchuck]

Before I added my argon bottle for my dry suit, I Had a 2lb weight in the bc back pocket to offset my 19 pony. Now with the 14 argon I don't need it any more. I just have one more lb in the argon side of my integrated BCD.

 

[texdiveguy]

SO if the tank IS negative how much weight (lead) can you loose. Or, let me rephrase, if the tank is negative wouldn't you DEDUCT lead for the negativity of the pony and first stage and then, MOVE some weight to counterbalance the weight of the rig?

PLUS I'd like to know how negative a 19cf pony and first stage is...

I persl. dive not having to use alot of wt.. By adding the small 19cf bottle slung I did have a bit more wt. because of the unit,,,this is fine in that if I do regr. the use of the bottle and it 'flips' by the time I reach the upper water column then I still will not have issues on safety stops. With a little practice diving a slung bottle is a piece-of-cake,,,,no off-balance issues at all for most divers.

 

[Sasquatch]

Yeah, good point texdiveguy. It'll sure get positive if you draw the air out of it.

But I know there is a way to figure the buoyancy of a full pony/stage, I'm just too beat to remember how...

 

[dannobee]

...But I know there is a way to figure the buoyancy of a full pony/stage, I'm just too beat to remember how...

Put the whole setup in a pool or bathtub, then weigh it with a fisherman's scale.

If for some reason you're sucking air from your pony, you're going to the surface anyway. I wouldn't worry about it getting light.

 

[divad]

I'd like to know how negative a 19cf pony and first stage is...

My Catalina 19 is 1.3#s negative when full and 0#s empty.

 

[srownin]

I love this board. I posted this question last night and already I have a lot of good information.

I actually don't have the pony on my tank, but under the bladder wing, ala the Zeagle zip mount. They may in fact be the main source of trouble. I also did realize that the tank and reg, even though the weigh 12lbs. would not be -12 in the water. Considering I do not have access to a fisherman's scale, is there any other good way to estimate +/- bouancy?

Thanks again for all of the help. I am going to the quarry in a few weeks and will probably take some time to tweak the set-up. If anything good comes of it, I will certainly share.

--Scott

 

[limeyx]

Put the whole setup in a pool or bathtub, then weigh it with a fisherman's scale.

If for some reason you're sucking air from your pony, you're going to the surface anyway. I wouldn't worry about it getting light.

It's the empty buoyancy that you want -- that's the worst case if you have empty main tank and empty pony, you still need to be able to stay down.

I would guess most ponies would be max 1-2 pounds positive with a regular 1st stage on them. AL40 gets a little positive when empty.

 

[limeyx]

I love this board. I posted this question last night and already I have a lot of good information.

I actually don't have the pony on my tank, but under the bladder wing, ala the Zeagle zip mount. They may in fact be the main source of trouble. I also did realize that the tank and reg, even though the weigh 12lbs. would not be -12 in the water. Considering I do not have access to a fisherman's scale, is there any other good way to estimate +/- bouancy?

Thanks again for all of the help. I am going to the quarry in a few weeks and will probably take some time to tweak the set-up. If anything good comes of it, I will certainly share.

--Scott

Best solution:
1) Get the pony empty (200 psi or so) and your main tank down to 300 psi
2) *with a buddy* empty the BC and try to descend. you should be able to hang at 15 feet with the empty BC. Add/subtract weight until you can easily hold it there.

 

[ClayJar]

I have a 19cf pony on my left front from a shoulder ring to a hip ring. On my weight belt I have one 3# weight in the first pocket right of the buckle (as worn). That keeps me nicely trimmed. (I have no data on back-mounted pony bottles, as I'd researched and decided I'd be best served with a front-slung pony, considering my diving habits.)

 

[dannobee]

It's the empty buoyancy that you want -- that's the worst case if you have empty main tank and empty pony, you still need to be able to stay down.

I would guess most ponies would be max 1-2 pounds positive with a regular 1st stage on them. AL40 gets a little positive when empty.

You *guess*? Have you ever even dove with a pony? Tell you what, throw your pony rig in the ocean and see how positive it is. None that I know of are positive.

Mine stays full, and I rarely use it, and when I do, it's only for drills. If the emergency ever arises, I'll deal with being a pound or two underweighted.