cool_hardware52
Contributor
I mean that if my backplate, tank, etc are 15lb negative and I need 10lb(not 25)lead more to sink my undergarment, the whole rig becomes 25lb negative, thus the wing should be 25 or more.( As i understand the situation).
And why do you take into account only 15lb (without 10lb lead, which is supposed to be placed in the weight pockets on the harness)?
At the end of the dive you need enough ballast to offset the buoyancy of your suit (assuming you are close to neutral yourself)
For this calculation you need to use the empty buoyancy of your tank + plate, + harness + regs + lead.
To determine the minimum wing size you should use the large of:
The buoyancy required to float your rig at the surface with a full tank, if your ditch it
&
The max buoyancy your suit could lose, i.e. compression of a wetsuit, or total failure of a dry suit.
Tobin