CuriosityStream Documentaries
       
      CuriosityStream Documentaries
      Bright Now: Search for Japan's Lost Supersub (2019x120)
      
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      The I-400 was one of the Imperial Japanese Navy's Sen Toku-class submarines, which were the largest submarines ever built before the age of nuclear-powered subs. These massive vessels were longer than a football field and were used as submarine aircraft carriers.