This is not a rare illusion. When I used to be a kid, we saw this illusion all the time When we went to the beach in Albania (Port of Durres) The Adriatic see

This is not a rare illusion. When I used to be a kid, we saw this illusion all the time When we went to the beach in Albania (Port of Durres) The Adriatic see can be very calm sometimes, and the blue waters do match the same color/blue hue of the sky.