I always wondered about that CV3 effect (which is really really well-done, even if we cannot tell what it is).
Because the lines all move at odd directions, this leads me to believe it's air-based, not water-based, as water is, for the most part, pretty constant (unless it's something bad in the water like that effect of gasoline moving over slow water). Because of this, I'm with Inccubus in that I think it's supposed to be either Mist or Clouds.