Here is another way of looking at this.
[step one] An air bubble (balloon) is compressed to 264.6 p.s.i. (18 ATM) and this balloon (1) has a volume of 10 cubic feet after being compressed.
You raise balloon (1) 33 feet (1 ATM) to (17 ATM) and this balloon will expand to 20 feet cubic feet.
[step two] An air bubble (balloon) is compressed to 264.6 p.s.i. (18 ATM) and this bubble (2) has a volume of 10 cubic feet after being compressed and this balloon is attached to balloon (1)
You raise balloon (2) 33 feet (1 ATM) to (17 ATM) and this balloon will expand to 20 feet cubic feet while balloon (1) rises 33 feet as well and expands to 40 cubic feet.
One (1) cubic foot of displaced sea water has a lifting force of 64 pounds
...............Balloon one has displaced 40 cubic feet giving it a lifting force of 2,560 pounds.
Balloon two (2) has displaced 10 cubic feet of water giving it a lifting force of
640 pounds.
Now the combined lifting force is 3,200 pounds
Do you agree or disagree with the above?

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