Optical illusion?

It's been a funny old day today. It hasn't really been cold, but it has been overcast and this afternoon it started to rain, lightly but steadily, and now we are in the middle of a thunderstorm. So I decided it was a good day to stay home and make a couple of birthday cards that I need for early in the new year. You're probably wondering why there is yet another 'sea and sky' photo at the end of this. Well, I was busy working away on my cards when Chris called me to see something from the verandah. The whole view of the sea and sky was grey and there was a dark line that clearly denoted the division between them, i.e. the horizon. Then I looked again where Chris was pointing, and above the aforementioned horizon there was a ship, apparently floating in the clouds! I took a photo, and when I downloaded it to the computer I could just see a feint second line beyond the ship which must be the actual horizon, but this hadn't been visible to our eyes. So here's my photo of a floating ship. Not very exciting, but my only offering for today!