The term DEVIATE FROM COURSE can be summarized as changing direction or straying from a predetermined path. YAW, which is a 3 letter word, is defined as the act of turning an aircraft or ship to the left or right. In aviation, yawing is the movement of the nose of the aircraft from side to side. In nautical terms, yawing is the movement of the bow of the ship from side to side. Therefore, the term DEVIATE FROM COURSE can be interpreted as yawing, or changing direction, from the original course.