 FACT: For various scenes, the submarine is incorrectly depicted as:  1. Flying the American Flag from the Sail (tower structure above  hull) while tied up at the pier, and 2. Not flying the American Flag  while underway (moving) surfaced. Ships and submarines throughout  the world: 1. Fly their national flag from their Stern (back end)  while tied up at the pier, and 2. Fly their national flag from their  Sail (submarines, surfaced) or Mast (surface ships) while underway.