ELSA will not work! You assume that the cylinder will expand after dropping down into water. But the water pressure is greater at the bottom. The pressure will rise 0.433 PSI for each foot of depth. So at say 35 feet the pressure will be a little over 15.15 PSI above atmosphere pressure. When the piston expands the inside air pressure drops. To expand to douple size the pressure must drop to half. So the pressure inside the cylinder before expansion must be about 30.3 PSI. When expanded the cylinder displaces 32 pounds of water. Assuming the cylinder's cross sectional area is one square foot then the cylinder will lift about 34 cubic feet of water 6.15 inches above the surface. The 6.15 inches of water produces a pressure of 0.22 PSI. This is no where near enough to re-compress the air back to 30.3 PSI needed at the bottom to expand the cylinder. You would need a column of water close to 70 feet high.

If you used a pressure multiplying cylinder you could convert the 32 pounds of water into 1 pound of water at about 16 feet high which would give you about 7.1 PSI, still not enough to re-compress.

You might think a vacuum would work but then you need to pull the cylinder to expand it which requires the same energy as compressing it.

Jim_Mich

1>>? ? ? ?MODIFY YOUR WRONG POST THAT SAY -doesnt work-? THIS IS SCARING PEOPLE THAT HAVE INTENTIONS ON TRY.?
2 >>? ? ? SUBMARINES DON?T LIFT UNDER OCEAN WATER PRESSURE? ->(im thinking of you as oil companies manipulator)? ?
3>>? ? ? ?AS TERRY SAYS -WATER IS NOT TRAPED ON THE TUBE.
3 >>? ? ? FINISH READING THE ELSA RELATED MATERIAL FIRST BEFORE SAY ANITHING !? ?
4 >>? ? ? RIDICULOUS! to say anithing like that make this discartable.? ?

(For DIFFERENT ELSA  WTH TRAPPED WATER DEVICE ALSO WORKS!? Just setting away a new format of shutle that lock the top before reach the botton, and use pressure of water passing trough a donut to botton of shutle to self expand again using valves to keep air!!!)  
Aslo remember that the OUT TUBE IS THINER. Water WILL go up for sure.

Read this!
http://www.theverylastpageoftheinternet.com/forsale/plans/elsa/751.gif

We need to do the COMPLETE SETUP before have SURE of anithing.

Im warrior...Im not afraid OF D**M MULTINACINALS at all, yet will need to try kill people like me.
 IM BURNING WITH ANGER!

Regarding this device, I am with Jim on this one. Jim is correct regarding the increase in water pressure as you descend. It won't work. And regarding submarines... Once they reach a certain depth they drop like lead balloons! They rely on their engines to raise them up... Not air!

from what i can understand the piston is never pumped with air because it is a sponge/foam kind of piston, it moves up the cylinder pushing water up into tank. the water that was pushed up is a lot heaver than the foam piston, this way you have more energy to push the foam-piston back down somehow to restart the whole prosses? what do you think?

That also would not work,
cause the upper water reservoir would move then down in height to
be able to push down the foam piston again.
So you would loose the potential energy of the water reservoir at the top...

There is always a catch, why these designs don?t work.
Believe me, I have tried it half a year to ponder about simular water systems
and all looked good at the first sight, but failed after deep analysis.

The only thing which might work is an imbalanced wheel which
has storage springs in it, so the movement of the weights inside the wheel is stored
just to imbalance the wheel and the springs will pull back the weights again,
so the weights are just oscillating inside the wheel to shift lever arms
and this just imbalances all the time a wheel
like the Bessler wheel and generates mechanical energy via the imbalancing.
But as the weights just only oscillate inside the wheel and imbalance it all the time,
there is a constant gain
from gravity field and the wheel can move on like the original Bessler wheel.

Regards, Stefan.

I'm glad there are some people starting to think more clearly about buoyancy drives.

"Are they all this angry?"
Maybe not, but they sure can be persistent.

"0.433 psi per foot of depth?"
Sounds good to me. I figure one atmosphere per 33 feet. So 14.7 psi / 33 feet = 0.445 psi/foot, which is "close enough" for government work, as they say.