SM U-27 was a German Type U-27 U-boat built for service in the Imperial German Navy.
She was launched on 14 July 1913, and commissioned on 8 May 1914 with Kapitänleutnant Bernd Wegener in command.
On 18 October 1914, the British submarine  was torpedoed and sunk in the North Sea by U-27.
This was the first action in which one submarine sank another.
Sinking of HMS ''E3''
had sailed from Harwich on 16 October to patrol off Borkum in the North Sea.
On 18 October, E3 spotted some German destroyers ahead but was unable to get into a position to take a shot at them.
Unable to pass them, Commander Cholmley retreated into the bay to wait for them to disperse.
As he did so, he failed to see that the bay was also occupied by U-27, under Kapitänleutnant Bernd Wegener.
Wegener was surfaced and patrolling between the Ems and Borkum when at 11:25, an object resembling a buoy was spotted where no buoy should be.
Suspecting a British submarine, U-27 immediately dived and closed the object.
Although the enemy was ‘conned down’, the number 83 was clearly visible on the conning tower of the British boat, now identified as such beyond reasonable doubt.
Wegener tracked the submarine for two hours until able to approach ‘up sun’.
He noted that the look-outs were staring intently in the other direction, towards the Ems.
When the distance had closed to , U-27 fired two G6 torpedoes.
An explosion 12 seconds later sank E3 immediately.
The KTB records that men (probably the look-outs from the bridge) were visible in the water but U-27 dived and withdrew, fearful that a second British submarine might be lurking nearby.
30 minutes later, the U-boat returned to the scene to search for evidence and possible survivors but without success.
All 28 members of E3s crew were lost.
Other encounters
31 October 1914, U-27 sank the seaplane carrier  in the Straits of Dover, in position .HMS Hermes at www.wrecksite.eu
11 March 1915, U-27 sank the armed merchant cruiser HMS Bayano off Carswell Point, Stranraer at position .
18 May 1915 –  () was torpedoed and sunk by U-27 eleven miles NE of Trevose Head in Cornwall.
She was in ballast from Barry to Port Arthur, Texas.
19 May 1915 –  () was torpedoed and sunk by U-27 13 miles north of Trevose Head.
She was carrying coal from Cardiff to Livorno with the loss of two lives
Sinking and Massacre of the Survivors
On 19 August 1915, U-27 was sunk in the Western Approaches in position  by gunfire from Q-Ship , which had been using a neutral American flag as a false flag.
After the sinking of U-27, the surviving crew, including Bernd Wegener, were shot in the water and aboard the SS Nicosian, aboard which several survivors had climbed.
The Commander of HMS Baralong had received secret orders from the Admiralty to "take no prisoners from U-boats."
The massacre of U-27's crew violated the Hague Convention, which defines the killing of unarmed shipwreck survivors as a war crime.
The testimony of American sailors who had witnessed the massacre, caused an international incident.
The British Government refused to court martial the perpetrators of the massacre.
The Imperial German Government responded by adopting a policy of unrestricted submarine warfare.
Instead of surfacing and boarding Allied merchant ships, U-boats began to torpedo them on sight.
Many U-boat commanders cited the Baralong incidents and said, "It's their lives or ours.
No warning."
Summary of raiding history
References
Notes
Citations
Bibliography
