How much energy (Watts?) would be created by a balloon that was released under water? I am picturing a scuba diver's inflatable vest (a BC) that is suddenly inflated (assume zero air inside to begin with). Or more accurately if you have ever seen a free-diver who swims down a few hundred feet and then inflates the balloon that rockets them back up to the surface. In both cases, compressed air is released into a balloon-like vessel all at once. Assume the following: Depth released: 200ft below sea level Length of travel: 100ft (stops 100ft below surface) Volume of balloon: 3 cubic ft Balloon holds this 3 cubic ft of air at 100psi so it will inflate at 200ft- assumed .5psi per ft. (don't know if this is relevant) I am interested in how much energy is generated in the 100ft of travel towards the surface. Does the energy increase in direct relation to the length of travel or along some sort of a curve? A formula would be great so I could input different numbers. Thanks in advance for the help!