Leeway is just one of those things that is a law of the universe, just like gravity. Still with gravity - the advantage is that it's highly predictable. And so then is leeway. You will already know that leeway is the sideways slip motion of our sailboat down wind from the pressure of wind against our boat and sails, and always has to be taken into consideration. Airplanes suffer from the same issue. When flying in a cross wind, the plane crabs (slide slips) downwind. The course becomes different from the heading. Explaining leeway in detail: Not accounting for leeway ...