During the First World War the German government made extensive use of submarines, initially against warships and then, as the war progressed, most heavily against merchant shipping. read more
British World War I submarines were widely used in the Baltic Sea, including the successful 1915 German blockade. Because so many merchant ships were sunk in that operation, the Germans were forced to introduce a convoy escort system. Most World War I submarines were powered by diesel engines. A maximum speed of about 17 km per hour was standard, and most submarines stayed near the surface as much as possible. Several inventions helped to make World War I submarines more effective. read more
Although experimental submarines had been built before, submarine design took off during the 19th century, and they were adopted by several navies. Submarines were first widely used during World War I (1914–1918), and now figure in many navies large and small. read more
Submarine. Although submarine was first deployed as a weapon during the American War of Independence more than a century before World War I, it was first widely used only during World War I - mainly to disrupt enemy supply lines. read more