U-boats were a major part of WWI. They played a very large role at the war at sea. the destruction of enemy shipping was done by U-boats. The sinking of the Lusitania was also done by a German U-boat. Germany was the first country to employ submarines instead of other battle ships. These U-boats were so important because they caused so much damage during WWI. U-boats were important because they sunk many many ships with torpedoes.
Wilhelm Bauer was a German inventor and engineer who designed the U-boat. Schweffel and Howaldt built the first German U-boat. This vessel was built in Germany in Kiel harbor. This submarine was named the Brandtaucher and needed three men to operate it.
Many torpedoes that the U-boats used to destroy ships were self-propelled. When a torpedo is self-propelled it means that it is manually driven by a person into its target. This means that basically the person that is driving the torpedo manually is going to die. This type of torpedo killed some every time someone got into one.
The U-boats took place largely in the Mediterranean Sea. They also fought in the British Isles. The Mediterranean Sea is a large body of water surrounded by many countries. In 1914 when they went to attack Royal Navy warships in the North Sea, by the end of this campaign the German had sunk 9 warships but had lost 5 of their own number.
This is a modern submarine. Submarines have changed drastically since WWI. Submarines are now a lot bigger and a lot safer. These modern submarines are a lot more efficient and have all the new technology to make them the best they can be. Some examples of how they are better than they were during WWI is that they are a lot faster in speed and can contain more weapons for war if needed.
Submarines have taken very large steps over time as you can see in the image above. For example, the one in 1900 is almost microscopic compared to the one in 1980. Submarines are still a big part of the world especially in war but in WWI they were unthinkable. If the U-boat was never created there might have never been WWI. I think this because some historians think the reason the U.S. got involved was because of the sinking of the Lusitania. A German U-boat sunk the Lusitania so without U-boats the Lusitania might have never been sunk and a lot more people could maybe still be alive today.