SM UC-4 was a German Type UC I minelayer submarine or U-boat in the German Imperial Navy during World War I. The U-boat had been ordered by November 1914 and was launched on 6 June 1915. She was commissioned into the German Imperial Navy on 10 June 1915 as SM UC-4. Mines laid by UC-4 in her 73 patrols were credited with sinking 36 ships. UC-4 was scuttled off the coast of Flanders during the German evacuation on 5 October 1918.
SM UC-11 was a German Type UC I minelayer submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 23 November 1914, laid down on 26 January 1915, and was launched on 11 April 1915. She was commissioned into the German Imperial Navy on 23 April 1915 as SM UC-11. Mines laid by UC-11 in her 83 patrols were credited with sinking 27 ships. UC-11 was mined and sunk on 26 June 1918. A crew member was Rudolf Finkler from Oberlinxweiler, Kreis St. Wendel, Germany. According to his death record the boat went down in the North Sea near Harwich, abt. 2.5 nautical miles north east of Funk Feuerschiff on position 51°55′N1°41′E.
SM UC-14 was a German Type UC I minelayer submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 23 November 1914, laid down on 28 January 1915, and was launched on 13 May 1915. She was commissioned into the German Imperial Navy on 5 June 1915 as SM UC-14. Mines laid by UC-14 in her 38 patrols were credited with sinking 20 ships, one of which was the Italian pre-dreadnought battleship Regina Margherita, which at 13,427 tonnes displacement was one of the largest ships sunk by U-boats during the war. UC-14 was mined and sunk on 3 October 1917.
SM UB-23 was a German Type UB II submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 30 April 1915 and launched on 9 October 1915. She was commissioned into the Imperial German Navy on 13 March 1916 as SM UB-23. The submarine sank 49 ships in 21 patrols for a total of 28,228 gross register tons (GRT). On 26 July 1917, UB-23 was badly damaged by a depth charge attack by HMS PC-60 off the Lizard; she put in at Corunna, Spain, on 29 July 1917 and was interned. On 22 January 1919 she was surrendered to France in accordance with the requirements of the Armistice with Germany, and she was broken up in Cherbourg in July 1921.
SM UB-30 was a German Type UB II submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 22 July 1915 and launched on 16 November 1915. She was commissioned into the German Imperial Navy on 18 March 1916 as SM UB-30.
SM UC-17 was a German Type UC II minelaying submarine or U-boat in the Imperial German Navy in World War I. She was ordered on 29 August 1915 and launched on 29 February 1916. She was commissioned into the Imperial German Navy on 21 July 1916 as SM UC-17.
SM UC-22 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 26 August 1915 and was launched on 1 February 1916. She was commissioned into the German Imperial Navy on 30 June 1916 as SM UC-22. In 15 patrols UC-22 was credited with sinking 23 ships, either by torpedo or by mines laid. UC-22 was surrendered to France on 3 February 1919 and was broken up at Landerneau in July 1921.
SM UC-25 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 29 August 1915 and was launched on 10 June 1916. She was commissioned into the German Imperial Navy on 28 June 1916 as SM UC-25. In 13 patrols UC-25 was credited with sinking 21 ships, either by torpedo or by mines laid. March–September 1918 she was commanded by Karl Dönitz, later Grand admiral. UC-25 was scuttled at Pola on 28 October 1918 on the surrender of Austria-Hungary.
SM UC-71 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy during World War I. The U-boat was ordered on 12 January 1916 and was launched on 12 August 1916. She was commissioned into the German Imperial Navy on 28 November 1916 as SM UC-71. In 19 patrols UC-71 was credited with sinking 61 ships, either by torpedo or by mines laid. UC-71 sank on 20 February 1919 in the North Sea while on her way to be surrendered.
SM U-56 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-56 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM U-58 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-58 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM U-59 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-59 was engaged in the naval warfare and took part in the First Battle of the Atlantic. She struck a German mine and broke into two parts at Horns Reef at about midnight on 14 May 1917. She lost 33 of her crew; there were 4 survivors. The wreck of U-59 was located in 2002.
SM U-60 was a German Type UB III submarine of the Imperial German Navy in the First World War. She took part in the First Battle of the Atlantic.
SM U-100 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-100 was engaged in the German campaign against Allied commerce (Handelskrieg) during that conflict.
SM U-14 was one of the 329 submarines serving in the Imperial German Navy in World War I.
SM U-22 was one of 329 submarines serving in the Imperial German Navy in World War I. U-22 was engaged in commerce war as part of the naval warfare, during the First Battle of the Atlantic.
SM U-23 was one of the 329 U-boats serving in the Imperial German Navy in World War I.
SM U-136 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-136 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM UB-64 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. She was commissioned into the German Imperial Navy on 5 August 1917 as SM UB-64.
SM UB-78 was a German Type UB III submarine or U-boat in the German Imperial Navy during World War I. She was commissioned into the German Imperial Navy on 20 October 1917 as SM UB-78. Mined off Dover on 19 April 1918 all 35 crew lost.
Germany 
