I am a firm believer in knowing the night sky, especially the Big Dipper and the NS. It has come in handy for me when navigating in areas where local variation (iron in lava flows was deflecting the needle).

If you are ever steering a ship at night, it is much easier to pick a star that is on your course, and steer by that, rather than constantly consulting the ship's compass. Over a few hours, you may need to change stars, but that is easy to accomplish (as long as cloud cover doesn't interfere).

If there are clouds present, it really helps to know some of the other constellations to at least determine approximate directions. This requires study before hand.