A man was walking along the coast of the United Kingdom this week when he was taken aback by what seemed to be a huge ship floating through the sky in the distance. His incredible photographs reveal an optical illusion created by a peculiar “superior mirage.”

On Thursday 52-year-old businessman David Morris was strolling along the beach in the Cornish village of Gillan when he discovered the strange sight. Before the phenomenon passed he was able to pull out his mobile and take a series of pictures of the flying ship.

David Morris/Apex
David Morris/Apex

The photographs tend to show signs of a phenomenon known as fata morgana a Met Office spokesperson says. “A rare and complex form of mirage in which objects are distorted horizontally and vertically inverted and elevated in shifting patterns.

The effect is caused by the superposition of multiple layers of air with different refractive indices over a water surface.

Since the light from the straw is bent by three different mediums (and refractive indices) of air glass and water it can appear broken when placed in a glass of water. In Morris picture the same concept is at work with layers of air bending light in different ways.

Superior mirages are caused by a weather phenomenon known as a temperature inversion in which cold air is above the sea and warmer air is above it. BBC meteorologist David Braine tells BBC News, because cold air is denser than warm air it bends light into the eyes of someone standing on the ground or along the shore altering the appearance of a distant object.”

These kinds of mirages can make distant ships appear to be floating above where they aren’t but they can also make ships below the horizon visible when they wouldn’t otherwise be. Superior mirages are more common in the Arctic regions of the globe according to Braine but can be seen very rarely further south in the winter such as in the UK.

Morris says, “I was just in awe of the image in such a lovely part of the country.”

Image credits: Header image cropped from photo by David Morris/Apex