Humanities › History & Culture World War I at Sea Share Flipboard Email Print The sinking of the Cunard ocean liner 'Lusitania' by a German submarine off the Old Head of Kinsale, Ireland. 128 US citizens lost their lives and the tragedy helped bring the USA into World War I. (May 7, 1915). (Photo by Three Lions/Getty Images) History & Culture Military History World War I Battles & Wars Key Figures Arms & Weapons Naval Battles & Warships Aerial Battles & Aircraft Civil War French Revolution Vietnam War World War II American History African American History African History Ancient History and Culture Asian History European History Genealogy Inventions Latin American History Medieval & Renaissance History The 20th Century Women's History View More By Robert Wilde History Expert M.A., Medieval Studies, Sheffield University B.A., Medieval Studies, Sheffield University Robert Wilde is a historian who writes about European history. He is the author of the History in an Afternoon textbook series. our editorial process Robert Wilde Updated October 24, 2017 Before World War I, Europe’s Great Powers assumed that a short land war would be matched by a short sea war, where fleets of large heavily armed Dreadnoughts would fight set-piece battles. In fact, once the war began and was seen to drag on longer than anticipated, it became apparent that the navies were needed for guarding supplies and enforcing blockades - tasks suitable for small vessels - rather than risking everything in a large confrontation. Early War Britain debated what to do with its navy, with some keen to go on the attack in the North Sea, slashing German supply routes and trying for active victory. Others, who won, argued for a low key role, avoiding losses from major attacks in order to keep the fleet alive as a Damoclean sword hanging over Germany; they would also enforce a blockade at distance. On the other hand, Germany faced the question of what to do in response. Attacking the British blockade, which was far enough away to put Germany’s supply lines to the test and comprised of a larger number of ships, was hugely risky. The spiritual father of the fleet, Tirpitz, wanted to attack; a strong counter group, who favored smaller, needle-like probes which were supposed to slowly weaken the Royal Navy, won. The Germans also decided to use their submarines. The result was little in the way of major direct confrontation in the North Sea, but skirmishes between the belligerents around the world, including in the Mediterranean, Indian Ocean and Pacific. While there were some notable failures – allowing German ships to reach the Ottomans and encourage their entry into the war, a thrashing near Chile, and a German ship loose in the Indian Ocean – Britain wiped the world sea clear of German ships. However, Germany was able to keep their trade routes with Sweden open, and the Baltic saw tensions between Russia – reinforced by Britain – and Germany. Meanwhile, in the Mediterranean Austro-Hungarian and Ottoman forces were outnumbered by the French, and later Italy, and there was little major action. Jutland 1916 In 1916 part of the German naval command finally persuaded their commanders to go on the offensive, and a portion of the German and British fleets met on May 31st at the Battle of Jutland. There were roughly two hundred and fifty ships of all sizes involved, and both sides lost ships, with the British losing more tonnage and men. There is still debate over who actually won: Germany sunk more, but had to retreat, and Britain might have won a victory had they pressed. The battle revealed great design errors on the British side, including inadequate armor and munitions which couldn’t penetrate German armor. After this, both sides demurred from another large battle between their surface fleets. In 1918, angry at the surrender of their forces, the German naval commanders planned a final great naval attack. They were stopped when their forces rebelled at the thought. The Blockades and Unrestricted Submarine Warfare Britain intended to try and starve Germany into submission by cutting as many seaborne supply lines as possible, and from 1914 – 17 this only had a limited effect on Germany. Many neutral nations wanted to keep trading with all the belligerents, and this included Germany. The British government got into diplomatic problems over this, as they kept seizing ‘neutral’ ships and goods, but over time they learned to better deal with the neutrals and come to agreements which limited German imports. The British blockade was most effective in 1917 – 18 when the US joined the war and allowed the blockade to be increased, and when harsher measures were taken against the neutrals; Germany now felt the losses of key imports. However, this blockade was dwarfed in importance by a German tactic which finally pushed the US into the war: Unrestricted Submarine Warfare (USW). Germany embraced submarine technology: the British had more submarines, but the Germans were larger, better and capable of independent offensive operations. Britain didn’t see the use and threat of submarines until it was nearly too late. While German submarines couldn’t easily sink the British fleet, which had ways of arranging their different sizes of ships to protect them, the Germans believed they could be used to effect a blockade of Britain, effectively trying to starve them out of the war. The problem was that submarines could only sink ships, not seize them without violence as the British navy was doing. Germany, feeling that Britain was pushing the legalities with their blockade, began to sink any and all supply ships heading for Britain. The US complained, and German back peddled, with some German politicians pleading for the navy to select their targets better. Germany still managed to cause huge losses at sea with their submarines, which were being produced faster than Britain could either make them or sink them. As Germany monitored British losses, they debated whether Unrestricted Submarine Warfare could make such an impact that it would force Britain into surrender. It was a gamble: people argued USW would cripple Britain within six months, and the US - who would inevitably enter the war should Germany restart the tactic – wouldn’t be able to supply enough troops in time to make a difference. With German generals like Ludendorff supporting the notion that the US couldn’t get sufficiently organized in time, Germany made the fateful decision to opt for USW from February 1st, 1917. At first unrestricted submarine warfare was very successful, bringing British supplies of key resources like meat to just a few weeks and prompting the head of the navy to announce in exasperation that they could not go on. The British even planned to expand from their attack at 3rd Ypres (Passchendaele) to attack submarine bases. But the Royal Navy found a solution they previously hadn’t used for decades: grouping merchant and military ships in a convoy, one screening the other. Although the British were initially loathe to use convoys, they were desperate, and it proved amazingly successful, as the Germans lacked the number of submarines needed to tackle the convoys. Losses to German submarines plummeted and the US joined the war. Overall, by the time of the armistice in 1918, German submarines had sunk over 6000 ships, but it was not enough: as well as supplies, Britain had moved a million imperial troops around the world with no loss (Stevenson, 1914 – 1918, p. 244). It has been said that the stalemate of the Western Front was doomed to hold until one side made a terrible blunder; if this was true, USW was that blunder. Effect of the Blockade The British blockade was successful in reducing German imports, even if it didn’t seriously affect Germany’s ability to fight until the end. However, German civilians certainly suffered as a result, although there is debate over whether anyone actually starved in Germany. What was perhaps as important as these physical shortages were the psychologically crushing effects on the German people of the changes to their lives which resulted from the blockade.