One of the major tension points which led to the beginning of the Great War was Germany’s attempt to build an imperial navy which dared to threaten the century-old British naval superiority. In 1906, Britain initiated a new era in naval weaponry when it unveiled the first modern battleship, the HMS Dreadnought, the most heavily-armed and armored to date. Since then, other major nations, including Germany, France, Italy, Austria-Hungary, Russia, the United States and Japan have scurried to modernize their fleets with these “all-big gun” ships.
At this point in time, the Royal Navy of the United Kingdom had ruled the seas for several centuries, but the German emperor Kaiser Wilhelm II and his naval minister, Alfred von Tirpitz, set out to change that, in part for strategic reasons, but mainly due to a simple desire to challenge Britain. The culmination of this race led to a stalemate in World War I. The German High Seas Fleet and the British Grand Fleet were too valuable to be risked in battle and so both spent the majority of the war in port, waiting to respond should the other go to sea. Paradoxically, the ships were too valuable (strategically, at least) to leave at port, and too expensive to use in battle. Apart from some operations in the Baltic against Russia, Germany's main fleet limited itself to making battlecruiser raids on the British east coast, in an attempt to lure part of the British fleet out so that it could be defeated by the waiting High Seas Fleet.
In their turn, the British made sweeps of the North Sea, and both sides laid extensive minefields. Although there were several naval battles, the only engagement between the main British and German fleets was the abortive Battle of Jutland, a German tactical victory (fourteen British ships were sunk to eleven German) but a British strategic victory, as the High Seas Fleet fled and mostly remained in port for the rest of the war.
Another major naval weapon to make its debut in the Great War was the submarine. While submarines were dangerous to operate, they would become effective weapons as they could lay mines and launch torpedoes undetected underwater. German submarines, or U-Boats, were very useful in attacking Great Britain’s merchant fleet in the attempt of starve the island nation of supplies. However, the unrestricted (meaning that submarine crews does not allow the crew of the targeted ship to abandon their vessel) submarine warfare against Great Britain would lead to American deaths and would help bring the powerful United States into the war against Germany.