SM U-19 was a German Type U-19 U-boat built for the Imperial German Navy. Her construction was ordered on 25 November 1910, and her keel was laid down on 20 October 1911, at the Kaiserliche Werft Danzig. She was launched on 10 October 1912, and commissioned into the Imperial German Navy on 6 July 1913.
SM U-32 was a German Type U 31 U-boat of the Imperial German Navy.
SM U-35 was a German U 31-class U-boat which operated in the Mediterranean Sea during World War I. It ended up being the most successful U-boat participating in the war, sinking 220 merchant ships for a total of 505,121 gross register tons (GRT).
SM U-55 was one of the six Type U-51 U-boats of the Imperial German Navy during the First World War.
SM U-9 was a German Type U 9 U-boat. She was one of 329 submarines serving in the Imperial German Navy, and engaged in commerce raiding (Handelskrieg) during World War I.
SM U-20 was a German Type U 19 U-boat built for service in the Imperial German Navy. She was launched on 18 December 1912, and commissioned on 5 August 1913. During World War I, she took part in operations around the British Isles. U-20 became infamous following her sinking of the British ocean liner RMS Lusitania on 7 May 1915, an act that dramatically reshaped the course of World War I.
SM U-68 was a Type U 66 submarine or U-boat for the German Imperial Navy during the First World War. She had been laid down in December 1913 as U-9 of the U-7 class for the Austro-Hungarian Navy but was sold to Germany, along with the others in her class, in November 1914. Under German control, the class became known as the U 66 type and the boats were renumbered; U-9 became U-68, and was redesigned and reconstructed to German specifications. She was launched in June 1915 and commissioned in August.
SM U-40 was a German Type U 31 U-boat of the German Imperial Navy during World War I.
SM U-38 was a German Type U 31 U-boat which operated in the Mediterranean Sea during World War I. It ended up being the third most successful U-boat participating in the war, sinking 134 merchant ships sunk for a total of 287,811 GRT.
SM U-17 was a German submarine during World War I. U-17 sank the first British merchant vessel in the First World War, and also sank another ten ships, damaged one ship and captured two ships, surviving the war without casualty.
SM U-53 was one of the six Type U 51 U-boats of the Imperial German Navy during the First World War.
SM U-33 was a German Type U 31 U-boat of the Imperial German Navy.
SM U-36 was a Type 31 U-boat in the service of the Imperial German Navy of the German Empire, employed in the commerce war in World War I.
SM U-92 was one of 329 submarines serving in the Imperial German Navy in World War I. She was engaged in the commerce warfare in the First Battle of the Atlantic.
SM U-65 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-65 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM U-78 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-78 was engaged in the naval warfare and took part in the First Battle of the Atlantic as a minelayer. On 27 October 1918 low frequency communications from U-78 in the Skagerrak were detected by the British submarine HMS G2 which sank her with the loss of her crew of 40. The commonly listed sinking date of 28 October 1918 is in error.
SM U-79 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-79 was engaged in the combat in the First Battle of the Atlantic.
SM U-96 was a Type U 93 submarine and one of the 329 submarines serving in the Imperial German Navy in World War I. U-96 was engaged in the naval warfare and took part in the First Battle of the Atlantic. She was launched in 1917. On 6 December 1917, she collided with the submarine SM UC-69 at Barfleur, France ; UC-69 sank with the loss of eleven of her crew. U-96 survived the war.
SM U-111 was one of the 329 submarines serving in the Imperial German Navy in World War I. She took part in the First Battle of the Atlantic.
SM U-18 was one of 329 submarines serving in the Imperial German Navy in World War I. U-18 engaged in the commerce warfare in the First Battle of the Atlantic.
German Empire 
