Something's been bugging me, and I have nothing in the way of education to know what the answer could be.
I was wondering if the speed of an air bubble would change if the water it was in was moving in the opposite direction (i.e. the air bubble is going up and the water is going down). The speed would be based on the air bubble's actual movement, rather than the distance it has to cover to reach the water's surface.
Would differing movement speeds of the water make a difference? And, ultimately, would the air bubble speed up, maintain a consistent speed, slow down, stop, or even reverse depending on or regardless of how fast the water is moving against/around it?