SM U-90 was a Type U-87 U-boat of the Imperial German Navy during World War I. Its commander Walter Remy made regular stops at remote island North Rona for provisions such as fresh mutton. On 15 May 1918, U-90 shelled the Hirta wireless station in St Kilda, Scotland. On 31 May 1918, U-90 torpedoed and sank USS President Lincoln, a former Hamburg America Line steamer that had been seized by the United States for troop transportation. From the U.S. Navy crew that abandoned the sinking vessel, U-90 captured Lieutenant Edouard Izac, eventually taking him to Germany. Izac later escaped German captivity and reported to the US Navy about German submarine movements.
SM UC-1 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 26 April 1915. She was commissioned into the German Imperial Navy on 5 July 1915 as SM UC-1. Mines laid by UC-1 in her 80 patrols were credited with sinking 41 ships. UC-1 disappeared after 18 July 1917. UC-1 was sunk on 24 July 1917 by F2B Felixstowe flying boat. Standard practice was to fly along the U boat and drop 2 250lb bombs astride it, hoping to cause leaks and give time for a destroyer to collect the submariners and sink it. On this occasion, by fluke, one bomb went through the conning tower and blew the base out of UC1. MFG Mill was awarded the DFC for this but he refused to wear it because of the total loss of life <london Gazette> <MFG Mill Diaries>
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-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 16 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 51 ships in 21 patrols for a total of 33,880 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 UC-20 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 1 April 1916. She was commissioned into the German Imperial Navy on 7 September 1916 as SM UC-20. In 13 patrols UC-20 was credited with sinking 21 ships, either by torpedo or by mines laid. UC-20 was surrendered on 16 January 1919 and broken up at Preston in 1919–20.
SM UC-40 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 20 November 1915 and was launched on 5 September 1916. She was commissioned into the German Imperial Navy on 1 October 1916 as SM UC-40. In 17 patrols UC-40 was credited with sinking 30 ships, either by torpedo or by mines laid. UC-40 was being taken to surrender but foundered in the North Sea en route on 21 January 1919.
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 63 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. Discovery a century later of her wreck with all hatches open suggested she had been deliberately scuttled by her own crew.
SM U-47 was a Type U-43 submarine of the Imperial German Navy. She engaged in commerce raiding during the First World War.
SM U-57 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-57 was engaged in 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-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-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-80 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-80 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM U-98 was a Type U 93 submarine and one of the 329 submarines serving in the Imperial German Navy in World War I. U-98 was engaged in the naval warfare and took part in the First Battle of the Atlantic.
SM U-16 was one of the 329 submarines serving in the Imperial German Navy in World War I.
SM U-23 was one of the 329 U-boats serving in the Imperial German Navy in World War I.
SM U-52 was one of 329 submarines serving in the Imperial German Navy in World War I. U-52 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.
German Empire 
