World War II Secret Sub

This is one of the best documentaries about the war in the Pacific. Attached is a fifty-three minute documentary about an incredible and unknown super weapon of World War II. Germany had the V-2 rocket, the United States had the atomic bomb, and Japan had the super-sub.

The Largest Submarine in World War II: https://www.youtube.com/watch?v=OPC51Mh-jtU