The plane where the energy of the element of water flows from is a massive planet covered in an endless ocean. It is impossible for a land mass to exist above sea level as the water will rise to meet the surface. Air bubbles and underwater constructs are possible so there are giant fishbowl cities for the people of ISMA to enjoy fine and exotic fishes that only exist here.
Everyone knows the things like "you can't lick your elbow" and things like that, but did you know you can't hum while holding your nose? Go on, try it! It is also really hard to swallow while holding your nose. Not impossible, just hard. Try it!