You need to look at your drysuit undersuit or wetsuit. POSITIVE BOUYANCY = Drysuit & undersuit approx 8kg
wing gas 3kg so 8+3 = 11 kgs positive, therefore your already 11 kilos positive before you start.
NEGATIVE BOUYANCY Twin 12s 2KGS X2 =4KGS
BACKPLATE 3KGS
BREATHING GAS 3KGS
WEIGHTBELT 3KGS SO 4+3+3+3=13KGS LEAVES YOU 13 -11 =2KGS NEGATIVE (AT START OF DIVE BEFORE YOU USE ANY GAS) This is the reason why most use a P weight or V weight (approx 3kgs) on twinset and 2 to 4kgs on belt.I found that trying when id got 35 bar on twins at 6 metre shelf, loaded up with weight then take weight off until i could fin to surface was best for me. I then divided weight between twinset and belt.Im overweighted at start but i can still dump weight to make it to surface. At end of dive im nicely negative but still like to drop a bit more weight off,I think that will come whem im more confident at holding stops to within 0.5 metres
