Foiling technology has come a long way, allowing boats to soar above the surface, but that doesn’t mean boats can literally fly through the air–right?
David Morris may have been second guessing this for a moment when he saw a tanker ship hovering above the sea in Cornwall, England, while standing on a nearby hamlet. Alas, it was not a real-life hover boat, but the optical illusion was the product of phenomenon that is perhaps just as interesting.
Superior mirages are caused by a meteorological event called a temperature inversion. This is when warm air sits on top of cold air, rather than the temperature dropping with altitude. Though most common in the Arctic, the phenomenon can occur under certain conditions in other parts of the world. In the case of the flying tanker, cold air was resting above the cold sea, with warm air above.
Cold air is denser than warm air, which causes the light to bend towards the eyes of onlookers standing on the coast as is passes through the cold air, making the object to appear to be in a higher position than it actually is.
So, no, boats cannot really fly through the air–not yet at least. But when the weather conditions are just right, superior mirages will continue to confuse and fascinate mariners for the rest of time.