Why do people call businessmen "suits"? Or say that "planes fly" but not that "submarines swim"? When and where does an aircraft carrier "set sail"? What exact

Why do people call businessmen "suits"? Or say that "planes fly" but not that "submarines swim"? When and where does an aircraft carrier "set sail"? What exactly is "pre-boarding" at an airport? https://m.youtube.com/watch?v=vdPy5Ikn7dw&pp=0gcJCdgAo7VqN5tD https://m.youtube.com/watch?v=vdPy5Ikn7dw&pp=0gcJCdgAo7VqN5t...