A guy in Scotland saw a real life optical illusion when he looked out to the water in Banff. Check it out. I'll tell you below why it looks like the ship is floating.
Colin said that at first glance, he really did think the ship was floating in the air. Really, though, the optical illusion "was caused by a cloud formation closer to the shore which changed the colour of the water closer to the land. The boat, being further away, was in a cloudless area and therefore the sky reflected the sea making it look like the boat was floating."
There's also a video of it on Unilad taken by Colin.