If hes in a bubble, but not above the water, he would be underwater. Meaning he would float to stand above his bubble if there's enough water there, bringing the bubble with him keeping him underwater. So, he would shoot strait up like a rocket, or perhaps liftoff before the rain touches the ground...

Is there an upper range on the power? What if a waterworld a billion light years away is directly overhead? Dose he travel to a surface faster than his human form could survive?

How does he drink water? Is that why he needs to turn water to wine?

Ah yes, the Lotus effect.

Reminds me of those wizards in Discworld who are raised on dehydrated water, and can thus hover on water due to how much they hate its existence

Ah true. I guess he can just float then