Random : 5 things you didn't know about submarines

1. The word ‘submarine’ was first used in the 17th century as an adjective meaning ‘underwater’.
2. The first submarine boat was invented by German doctor Magnus Pegel in 1605.
3. He was one of the first to write about blood transfusions. His submarine sank in mud.
4. Then first working submarine was built in 1620 by Cornelius Drebbel. It was propelled by oars.
5.  USS Nautilus, the first nuclear submarine, was launched in 1954.