[David]

I already know how this is going to end but I ask anyway.

if a 3 liter bottle with open end has x lift at ten meters how much lift does it have at 70 meters. yes I know it will take more gas because of the presure but the volume 3 liters will remain the same. As the bottle rises to the surface the gas will expand and escape from open end but will it still have same lift at depth.

David :-)