Ways to Avoid Losing Oxygen in a Submarine
In 1940, German U-boat commander Otto Kretschmer's submarine was under siege for hours and his crew grew tremendously stressed. In order to preserve oxygen, they had to find ways to stay calm. (02:30)
In 1940, German U-boat commander Otto Kretschmer's submarine was under siege for hours and his crew grew tremendously stressed. In order to preserve oxygen, they had to find ways to stay calm. (02:30)