bio animation about marshmellow cannon

U- Boat

The U - Boat was a ship  submarine that was used 6 decades ago in the first world war. It was also seen in world war 2. Operated by Germany. An interested fact is there are only 4 of them left. Compared to the 56 of them 6 decades ago. The U-Boats were used to block of the supplies that British needed to survive. They were trying to starve them from blocking off all supplies they had needed. The U - Boats were also invented in the 1850's. Almost 10 decades ago from now. 

here's a video link that shows what the U - Boat is and what it does and what it looks like from the outside and inside.

https://www.youtube.com/watch?v=yXiSWPGy_gg