Submarines, also known as U-boats during World War I, are big underwater boats that were used in both WWI and WWII. World War I is the first time submarines were used and made a big impact. Germany was most known in World War I for their use with submarines. The Germans were the first to develop submarines for the war. By the start of the war they had 28 U-Boats made. They used three different kinds of submarines during the war, the biggest ones being the U-boats, and the other two kinds were smaller. They started their submarines against other warships and then they just targeted shipping goods. After the war they had to pay off millions for destroying the goods. Germany mostly targeted British merchant ships. It was encouraged by the
