In 1915, although the Germans attacked at sea, their bold plan to fall upon part of the British Grand Fleet with their entire High Seas Fleet, and thus achieve a superiority that would enable them to inflict serious casualties, affecting the overall situation at sea, was not pursued.
Admiral Franz von Hipper took the German 1st and 2nd Scouting Groups into the North Sea to attack British trawlers and patrol boats on the Dogger Bank. Intercepts by Royal Navy signals intelligence revealed the plans, and Admiral David Beatty was sent out with the 1st and 2nd Battlecruiser Squadrons to surprise Hipper, joined by the light cruisers and destroyers of the Harwich Force. Once Hipper realized that heavy British ships were present, he turned for home. Beatty’s flagship Lion drew first blood. Four British battlecruisers poured shells into the crippled Blücher until she sank, while Hipper led his battlecruisers home to safety.
The British failed to learn much from the demonstrable fallibilities in their command and control systems, in particular the weakness revealed aboard Beatty’s flagship Lion in the process of generating and signalling orders without incorporating ambiguities which fatally confused his subordinates in the stress of battle. Furthermore, the overall standard of gunnery demonstrated by the British battlecruisers was simply dreadful; while they could hit the Blücher well enough when she was a crippled standing target, they scored only a handful of hits on the other German ships.
The Germans were chastened by their experiences and shortly afterwards Admiral Friedrich von Ingenohl was dismissed from his command of the German Fleet. It was considered he had been remiss in not sailing with his fleet in support of the Dogger Bank operations and had taken unnecessary risks without the chance of any significant gain. He was replaced by Admiral Hugo von Pohl, a man who was to prove equally uninspired and hamstrung by the overall caution urged on the High Seas Fleet.
The opening stages of the naval war saw the Grand Fleet exercise a brooding distant presence while cruisers guarded the northern exits to the North Sea, enforcing the blockade which sought to prevent raw materials and supplies from reaching Germany. When it became apparent that the land war would not be over quickly, this became a key part of the Entente global strategy; this was after all why Britain was such a coveted ally. The blockade would endure throughout the whole war.
When the war began, submarines were regarded as a tactical adjunct to conventional surface ships. Yet a true commerce destroying role was considered largely impractical due to the limited range of many of the early submarines and the difficulties of following the dictates of international law when sinking merchantmen. Yet endemic dissatisfaction with the progress of the naval war, coupled with an unwillingness to risk the fleet in action left the Germans casting round for alternative plans in their efforts to inconvenience their naval adversaries. The solution set upon was to make a bonfire of international law.
Aside from using scarce resources, the submarine also faced serious deficiencies as a weapons system. In addition, submarines were slow, and this lessened their chance of maintaining contact and of hitting a warship moving under full steam. Submarines, however, benefited over time from an increase in their range, seaworthiness, speed, and comfort; from improvements in the accuracy, range, and speed of torpedoes; and from the limited effectiveness of anti-submarine weapons. In time, submarines came to play a significant role in naval planning.
The Germans declared a war zone of the seas surrounding Great Britain, meaning that any ship, enemy or neutral, caught inside its boundaries could be sunk at once. Instead of surfacing to stop, search and sink a ship, the U-boats would if necessary sink them by torpedo with no warning of any kind. Justification for this action was based on the assertion that the British had already broken international law by changing the definition of contraband goods for the Royal Navy blockade of Germany. But the real reason was to allow the U-boats to attack while still preserving their invisibility.
A large outcry followed the sinking of the Lusitania by the U-20. It was some ten miles off the Old Head of Kinsale, near Queenstown, Ireland, when it was struck by a torpedo fired by Lieutenant Walther Schwieger. In the end, of 1,959 passengers and crew, 1,195 were killed, of which 128 were American civilians. The uproar was enormous but the Germans were defiant, claiming that the liner was carrying contraband munitions and that their detonation had contributed to the ship’s speedy demise. But then 3 months later the U-24 sank the liner Arabic off Ireland. This time fatalities amounted to forty-four, of which only three were American citizens. Yet it sparked another furious round of US protests.
Germany was not alone in bending to destruction the international rules of law at sea. Special Service Vessels, code-named Q-ships by the British Admiralty, were created in response to U-boat attacks on merchant shipping. The Royal Navy took old tramp steamers and other vessels and fitted them with concealed guns. A U-boat coming upon such a vessel would not waste a torpedo on it, but instead closed with it on the surface. Once the U-boat approached, the Q-ship would unveil its guns and open fire. Manned by volunteers, the Q-ships achieved their first success in July 1915. In the course of the war they sank 14 U-boats.
The intense storm of American protest over the Lusitania and the Arabic dwarfed the relatively small-scale uproar over the manifest criminality of the Baralong incident. Germany was forced to institute a moratorium on attacks on any liners without prior warnings. In addition, her U-boats were redeployed to operations centered in the North Sea and Mediterranean where there was far less chance of annoying the Americans. This had the effect of releasing the pressure on Britain.
Italy’s decision to abandon Germany and Austria, with which it had agreed to a naval convention in 1913, and instead to join Britain and France in May 1915, ensured that the Mediterranean was controlled by this alliance.
In the Baltic, the Russian fleet was weaker than the forces the Germans could deploy if they moved in some of their High Seas Fleet units from the North Sea via the Kiel Canal. This indicated what the Americans could do at a far greater scale with the Panama Canal. Although there were battles off Riga in 1915 and 1917, this German capability encouraged Russian caution, which was also in keeping with a stress on the Russian army, with long established Russian naval doctrine, and with the Russian emphasis in the Baltic on local naval operations.
An Anglo-French fleet was sent to force open the Dardanelles en route to threatening Constantinople, the Turkish capital, itself. However, this poorly planned attempt was stopped by minefields, shore batteries, and an unwillingness, in the face of the loss of ships, to accept the risk of further naval operations. There had been a misplaced belief that naval power alone could force a passage through the Dardanelles, due to a serious underestimation of the Turkish minefields and the mobile shore batteries protecting them, and the Turkish ability and willingness to resist attack.