Ballast weights (weight integrated BC's)

[mcavana]

My BC has its main weight pockets located close to my waist. It also has 2 smaller weight pockets, one one each back shoulder. I have been slowly dropping weights trying to get to my perfect weight.

Please answer these questions first.

On a standard setup with an aluminum 80, is there any reason to use the pockets on the back shoulders? or should it all be in the main weight compartments?

I think it is to "trim" your swimming position, to make sure you are effortlessly parallell to the ground when swimming... but honestly I can't tell a difference if some of the weight is in the shoulder pockets.

 

[Will]

Necessary? No - but it can help some people trim out - but everyone is different based on their body and gear. A good rule of thumb is about a third of your total weight back there. On a back inflate it can also slightly help ease of flighting on your back at the surface.

 

[mcavana]

Ok, well here is the real question (and the reason this thread is in the solo section). I just added a 19cf pony to my setup as my backup. it will be mounted on the right side of my main tank. It is supposed to add about 2lbs of weight in the water.

Taking the added weight of the pony tank into account, my new ideal weights should be 18 lbs. It will be off balanced weight though because like I said the pony is on my right side making my right side heavy.

Now I know I pretty much have to figure this out by what works best for me, but in this situation, where would be a good starting point? If you have the pony bottle on your right side, and have to load up a total of 18 lbs in a weight integrated BC, how much would you put in each of the four pockets?

 

[mcavana]

Here is my BC http://www.diveaeris.com/p_bcs_atmoslx.html

Please note: it is a Hybrid bladder combines the benefits of both rear inflation and jacket style BCs

 

[Will]

IMO I would still start with the guideline as 3:1 main:trim - I would not weight your left side any heavier because of the tank as I doubt you will notice a difference. The 3:1 is just a starting point and you can move the weights around depending on your trim.

 

[DaleC]

Although the pony feels heavy on land you will not notice it in the water. I dive a slung Al 30 and a slung Al 80 and do not adjust the weights to compensate for them.

 

[mcavana]

IMO I would still start with the guideline as 3:1 main:trim - I would not weight your left side any heavier because of the tank as I doubt you will notice a difference. The 3:1 is just a starting point and you can move the weights around depending on your trim.

I know I am over thinking this but that is what I do so bare with me.

So is the general formula that 1/3 (66%) of the weight should be on the trim, or 1/4 (25%)? First you said a third, then you said a 3 to 1 ratio... and should I count the 2 lbs the pony is going to weigh in the equation?

 

[Will]

You are, i listed 1/3 as trim/weight ratio. 3/1 was weight/trim ratio. I would not remove weight for the pony as it is a negligible amount - and would no loner provide ballast if it was donated or breathed down.

 

[mcavana]

got it. thanks.

 

[b1gcountry]

Same thing, but here's my reason for it...
Whenever you are slinging a bottle, assume you will be ascending without it. If you do wind up leaving the bottom without the tank, or you are out of gas, and start breathing off the pony, you will no longer have that two pounds of extra weight, and at that point, something has gone wrong, and you don't want to add to your worries by being underweighted in addition to whatever else happened.

So, long story short, weight yourself the same as if you had no stages. If you want, move one pound from one pocket to the other, but a lot of people don't bother, and have no problems with it.

Tom

PS, Even if you're diving an AL80 as a stage, once you add a reg, SPG, and stage rigging, the tank will rarely if ever get positive; so no need to worry about the other end of the spectrum where you're adding weight to compensate for a buoyant stage and no backgas.