On the morning of 18 October 1914, between the river Ems and the island of Borkum, a U-boat commander named Bernd Wegener watched something that should not have been there. An object the shape of a buoy, in water with no buoy. He dived, closed the distance, surfaced just enough to look through his periscope, and made out the number 83 painted on a small conning tower. A British submarine, HMS E3, on patrol from Harwich. Wegener tracked her for two hours, manoeuvring patiently to attack from the sun-side where her lookouts could not easily see him. At three hundred metres he fired two G6 torpedoes. Twelve seconds later, the explosion took E3 down with all twenty-eight of her crew. It was the first time in history that one submarine had sunk another.
The killing of E3 was a marker. Submarines had existed in some form for decades, but they had been thought of as coastal nuisances - useful for harbour defence, perhaps for the occasional raid on shipping. Nobody had quite worked out what would happen when two of them met. Wegener's careful stalk gave the rest of the world its first answer. He returned thirty minutes after the strike to look for survivors - the war diary records crew members visible in the water just after the explosion, probably bridge lookouts thrown clear - but found nothing. He withdrew, worried that another British submarine might be lurking. From that moment forward, every navy with submarines knew that its boats were no longer safe from each other.
Through the autumn and winter, U-27 continued to make a name for herself. On 31 October 1914, she sank the seaplane carrier HMS Hermes in the Straits of Dover. In March 1915 she took the armed merchant cruiser HMS Bayano off the coast of Stranraer. In May she sank two merchantmen near Trevose Head in Cornwall: one in ballast from Barry to Port Arthur, Texas; the other carrying coal from Cardiff to Livorno, with two lives lost. Wegener and his crew were among the most successful of the Imperial German Navy's early submariners, operating in the closing North Sea and the western approaches to the British Isles. Their war, like the war of many U-boat crews, was the war of a new technology that was rewriting maritime conflict in real time.
On 19 August 1915, the same day a different U-boat sank the White Star liner SS Arabic, U-27 surfaced near a small steamer in the Western Approaches. The steamer was flying the neutral American flag. She was not what she appeared. She was HMS Baralong, a Royal Navy Q-ship - a heavily armed merchant ship disguised as a soft target, designed to lure submarines into surfacing close enough for concealed guns to do their work. Baralong hauled down the American colours, ran up the White Ensign, and opened fire. The engagement was one-sided and brief. Thirty-four shells found U-27 before she vanished in a hiss of compressed air and rumbling bubbles, leaving smoke over the water where she had been.
Twelve German sailors survived the sinking. They swam toward Baralong looking for rescue. They did not find it. Baralong's commanding officer Godfrey Herbert - operating under what an internal British inquiry described only as unofficial advice from two Admiralty Secret Service officers, 'Take no prisoners from U-boats' - ordered his men to shoot the survivors in the water. All twelve were killed. Herbert then sent twelve Royal Marines to a nearby merchantman, Nicosian, whose crew U-27 had been preparing to evacuate, with orders to kill any Germans found there. The killings violated the Hague Conventions on the conduct of war at sea. When word reached Germany the Reichstag debated the incident on 15 January 1916 and described it as cowardly murder. A commemorative medal was struck for the dead of U-27. The British rejected a proposed combined inquiry. The Prussian Ministry of War added the name 'Captain William McBride' - the false identity Herbert was using - to a black list of British officers wanted for war crimes. They could not learn his real name until after the war.
The wreck of U-27 lies somewhere in the Western Approaches, west of the Old Head of Kinsale, sixty-four nautical miles or so from the coast. She has never been definitively located. Her crew - the men killed by torpedo and shellfire, and the twelve killed in the water - rest with her. The Baralong Incident remained a propaganda touchstone in Germany through the rest of the First World War, useful to commanders who wanted to argue that the Royal Navy was capable of every cruelty German submariners stood accused of and more. The truth was uglier than either side wanted to admit: a war at sea that had stopped looking like anything either fleet had trained for, with no agreement on what counted as honourable any longer.
U-27 was sunk at approximately 50.72°N, 7.37°W, in the Western Approaches roughly 90 nautical miles south-west of the Old Head of Kinsale, Ireland. This is open Atlantic water; from cruising altitude on transatlantic routes near 50N, you may pass directly over the wreck site. The nearest Irish airport is Cork (EICK) about 130 km to the north-east. Visibility over this stretch of the Atlantic varies wildly with weather; on a clear day the long Munster coastline is visible to the north-east as a dark line above the horizon.