The plan is to take a million or more gallons of water at 330ft below the sea level and get it into the ocean.

Would the best way be to pump it back up to the surface using a low-electrical pump or a version of a hydraulic pump?

Or would it be easier to force the water to equal a pressure greater than that of the ocean at this depth and just pump it out at -330ft? The pressure of the ocean at this depth is quite high around 147psi.

The quantity of water that the pump can handle doesn’t have to be millions of gallons at once but one with a high capacity would be better. Any ideas?