There is a lot of science involved in wake patterns, a branch of fluid dynamics Wake - Wikipedia. The wake formed by a duck was explained by Lord Kelvin who died in 1907. you can see the wakes formed by ducks on a smooth lake when you are much too far away to see the duck itself. A lot of study and practice may have gone into it, but it is obvious as soon as you look down on a smooth sea, there are little "V" shapes all over the place.Can you tell us more about wake spotting? How long could a wake be for say a tanker, destroyer, trawler. I imagine the art of wake spotting developed by WW2