I was in Vegas and went to see Copperfield, mostly because no one else was playing and I have seen Penn and teller twice before. He did a gag where he has a girl that has not seen her father for years, come up and he and her vanish to an island where he picks up sand from the beach and she runs in the water. I think even though it looks fair it is a green screen back stage with good lighting and maybe a bit of real water to run in blended with the green screen. Does any one know if this is how it is done?