During the UFO waves of the 1940s and '50s a new type of peculiar, possibly extraterrestrial or covert machine was mentioned, and often sighted in the murky oceans of the world. The USO, or Unidentified Submarine Object, just like the flying saucers and mystery airships of before, had begun to cause panic. Were alien life forms monitoring our shores with their advanced technology and preparing for possible attack, or was the government conducting clandestine operations......