August 19, 1915 Lieutenant Godfrey Herbert of the merchant ship Baralong sank German submarine U-27 and shot 10 survivors in the water. Some of the Germans sought refuge aboard the SS Nicosian, which had been abandoned by its crew. Herbert sent marines aboard the Nicosian who killed the four remaining survivors.
September 24, 1915 HMS Baralong, renamed Wiarda, lured a German submarine U-41 into range and sank the U-boat with gunfire. After the Wiarda left the area two survivors climbed aboard an abandoned lifeboat. About three hours later the Wiarda returned and deliberately ran down the lifeboat.
April 13, 1940 The British navy sank the German ship the Erich Giese. The captain Karl Smidt reported that while the crew of 200 men were in the water, British destroyers opened fire on them.
May 20,1941 A convoy of 21 German ships was attacked by British warships off the coast of Crete during the night. Witnesses said the British ships scanned the sea with searchlights looking for the survivors, and opened fire on them. One survivor, Corporal Walter Segel, said: "I saw at least 20 groups of survivors who were illuminated by the British and then sprayed with bullets."
http://www.guardian.co.uk/print/0,3858, ... 90,00.html
The Baralong Incident was an unprosecuted war crime of World War I.
On August 19, 1915, U-27, commanded by Kapitänleutnant Wegener, was sunk by the Q-Ship HMS Baralong, commanded by Lieutenant Godfrey Herbert. Herbert ordered that all German survivors, including Wegener, should be executed on the spot. Although the British Admiralty tried to keep this atrocity a secret, news reached Germany and the "Baralong Incident" was used to justify increased cruelty at sea both during World War One and after.
http://www.nationmaster.com/encyclopedi ... g-Incident
This would have made a good research for our book but to be it happens in WW1...