The greatest sea battles of World War One


When most people think about World War One, they think about land warfare, involving trenches, bayonet charges and tanks. However, before the war even began, most military strategists believed that any future war would be won or lost on the sea. 


The world's superpowers had focused on developing the best battleships in preparation for war. Britain and Germany, in particular, had engaged in a naval arms race: Britain had the world's largest navy, while Germany wanted to compete with them. 


The most advanced battleship design at the time, was called the 'dreadnought'. Dreadnoughts were a revolution in ship design. They were fully metal ships, with massive gun arrays on their decks. When the first dreadnought was made by Britain, no other ship could sink it. Britain built many more dreadnoughts, while Germany rushed to have as many as possible. However, by the time WWI had begun, no-one had actually used them in battle, and all ship commanders had to 'learn on the go'. 


War begins

At the start of World War One, Britain used its higher numbers of ships to control the oceans around Germany. Most importantly, it blockaded the ports of Germany and its allies. This prevented trades ships from reaching these countries with vital supplies of industrial materials and food. By starving the German population and limiting the number of weapons they could build, Britain was limiting the effectiveness of their enemy's armies.


To counter-act the trade blockade, Germany relied upon another new technology: submarines. German submarines were called 'U-boats'. At the beginning of WWI, no-one had developed a defense against submarines, and they could sink a multi-million dollar battleship with a single torpedo. In September 1914, one submarine sank three British battleships.


As a result, ship commanders became terrified of sending their expensive dreadnoughts out of the harbour incase a U-boat sunk them. For the first two years of the war and into 1916, Britain developed a range of countermeasures to stop the U-boat menace, including minefields, nets, depth charges and scouting patrols, but they were not very effective.


As a result of the fear induced by submarines, there were no major naval battles during the first half of the war. Both sides believed that if they could get into a fight with the other side's navy, they could have a decisive victory and win the war. However, to get into a battle, each side had to entice the other to sail their fleets out of their harbours. 



The Battle of Jutland

Finally, an opportunity to fight a major naval engagement with dreadnought fleets came on the 31 May-1 June 1916. The British Grand Fleet was alerted to the presence of the Germany navy in the North Sea, near Denmark, and sailed out of the harbour. The two navies clashed in the Battle of Jutland


The Germany fleet had fewer ships, but the British fleet suffered the first casualties by losing two ships early. The guns on the dreadnought ships on both sides were so powerful that both fleets rarely saw each other during combat, which lasted all day and all night. By morning, both fleets returned home, suffering significant losses. 


While both sides claimed victory, there was no overwhelming win for either country. Britain had lost more ships, but Germany didn't allow its fleet to leave harbour for the rest of the war, handing control of the North Sea to its enemy.


As a result, the Battle of Jutland was to be the only significant naval battle of the war, and it showed the irrelevance of battleship combat to the wider war. 

Source:,_1916.svg. Used under  Creative Commons Attribution-Share Alike 3.0 Unported.
Source:,_1916.svg. Used under Creative Commons Attribution-Share Alike 3.0 Unported.

Unrestricted submarine warfare

Following the Battle of Jutland, Germany returned to focusing on submarine warfare. It believed that if it could simply sink the opponent's ships, it would no longer have to risk its own.


On the 1st February 1917, Germany announced 'unrestricted submarine warfare', which meant that they would shoot any ship they considered to be helping the Allied cause. This included merchant or trading ships, particularly in the Atlantic Ocean. By doing this, Germany hoped to weaken Britain's position in the war, similar to how Britain's blockade of Germany's ports was weakening them.


The result of unrestricted submarine warfare was catastrophic for British shipping. Huge numbers of merchant ships were sunk by U-boats and the British government had to limit its use of resources for the war.


To limit the damage caused by the German submarines, Britain and its allies developed the 'convoy' system. A convoy was a group of ships that worked together to protect merchant shipping. Warships were sent to escort trade and passenger ships by detecting and shooting at U-boats. By the end of 1917, this new system had effectively neutralised the U-boat threat and Britain had control of the seas once more. 

Further reading