BCD/Wing Lift Theoretical Disscusion

[1_T_Submariner]

If they made Wings/BCD Lift capacity like they do weights (Ie Pound increments). How would how would you determine what lift capacity you would buy?

Ok one step further Money is no object so you can have a few for different conditions or situations that you might want to dive in. Money is no object in purchasing the gear taking it places still is.

I have a theroy on how I think the capacity should be sized just curious what the scubaboard comunity thinks. Making an assumption that a lot of people start out like I did bought a BC with never giving this any thought more on this later.

Thanks for your time and input in advance.

 

[Kern]

With a BP= 6lb, tank & gas 10lb, reg 2lb, bands & other hardware= 4lb. Sum of 22lb negative rig.

With a 5/7 wet suit I wear a weight belt with 9lb of lead.
With a dry suit & Mk 2 undies I have 12lb on a belt.

Wet suit about 15lb +; dry suit about 20lb +.

I'd be at least a 1lb or 2lb overweight in the wet suit, & about 1lb or 2lb light in dry suit. Shrink wrapped at 3mts..

I chose a 26lb wing as it would float my rig at the surface, & account for the loss of all buoyancy from my exposure protection.

Even though winter diving only amounts to about 20% of my diving, I have been thinking of changing my winter config. I'd like to remove 8lb from the weight belt by adding it to the BP. My rig would then be 30lb neg. & my weight belt 4lb. I could also add a pound or 3 to the belt. Of course I'd now need a wing of around 35lb lift to float the rig at the surface. If I ever required any dwezzle ++++ dry suit undies they may be around 30lb or so +, & may become the limiting factor. Still, I figure a 35lb wing will do the job.

 

[TSandM]

I think Tobin explains it extremely well.

Your wing has to do two things: float your rig at the surface, and compensate for the lift you can lose from your exposure protection at depth. Whichever is greater, determines the lift.

My dry suit with undergarments is 28 pounds positive. So I could, conceivably, lose 28 pounds of positive force in a full flood. My wing would need to compensate for that, so it needs to be at least 28 pounds in lift.

My rig is a 5 lb backplate, 6 lbs of camband weights, 2.5 lbs or so of regulator, and about 6 lbs of usable gas. That's about 19.5 lbs of things that want to sink -- a 28 pound wing will do that very adequately.

I use a 30 lb singles wing, which meets both criteria.

Wings for different water conditions, or for doubles, can be selected using the same method.

 

[sea2summit]

Once you get away from jacket style PCs I can't think of one that isn't sold based on the weight it displaces. And yes you might end up with 2-3 for varying conditions, I had a single tank wing and a doubles wing.