Another pony question

[Garrobo]

I accidentaly posted this under Accidents. Sorry. It was an accident. ==== I'm 180 pounds, 3mm full wetsuit, no gloves, hood or booties, BCD and 14 pounds of lead in salt water. How much more or less lead would I need with a 13cu pony?

 

[sheck33]

I accidentaly posted this under Accidents. Sorry. It was an accident. ==== I'm 180 pounds, 3mm full wetsuit, no gloves, hood or booties, BCD and 14 pounds of lead in salt water. How much more or less lead would I need with a 13cu pony?

Well, I have a 30cuft cylinder laying here so I'll do a rough gestimate for that tank, the idea is the same for your tank.

You need to be able to be neutral with that tank empty so:
my empty 30cuft tank weighs about 14lbs (so you add 14lbs of negative buoyancy by adding the tank)
The volume of the physical tank is about 18 (lenght)x19(surface area bottom)= 342 cubic inch = .2 cu ft. The tank displaces .2 cuft of seawater, taking the density of seawater as about 64 lbs/ft^3, this adds roughly 12 lbs of positive buoyancy. Overall, you would be able to remove about 2 - 3 lbs of your weight belt.

I think it will be in about the same range for your 13 cuft tank.

Someone correct me if I made a mistake somewhere.

 

[ScubaSarus]

2 lbs is about right for a 13 cf tank ; you are right on. Depending how the tank is worn, one may want to put the 2 lbs on to counterbalance the tank. I sling mine so the 2lbs go on the opp. side.

 

[sheck33]

The best way is of course to just dive the setup and figure it out by experimenting with weights.

 

[sheck33]

Sarus: What are you saying no to? I'm confused. The weight difference is not going to be very much in any case. The buoyancy numbers are independent of how the tank is worn though.

 

[ScubaSarus]

No that you are not wrong lol I edited it.

 

[texdiveguy]

I accidentaly posted this under Accidents. Sorry. It was an accident. ==== I'm 180 pounds, 3mm full wetsuit, no gloves, hood or booties, BCD and 14 pounds of lead in salt water. How much more or less lead would I need with a 13cu pony?

To be very honest....I would not really worry about---not that you probably are....but slinging a 13cf pony is not going to be a big deal...just use your normal wt.. As far as counter balancing for an Al13 there is no reason one should have to do this, it will not cause you to list to one side.

 

[sheck33]

Sarus: Ah, okidoki then

 

[charlesml3]

Yep, my aluminum 13 foot pony is 2.7 pounds negative with the regulator attached. I checked it with a bit of rope and a fish scale once.

I band it to my tank on the right so I keep 3 more pounds on the left side of my BC to compensate. Works just fine...

-Charles

 

[Garrobo]

Charlesml3 :: Thanks for the answer that I was looking for. And thanks to all the others for their suggestions, advice and opinions.