SM UC-75 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 12 January 1916 and was launched on 6 November 1916. She was commissioned into the German Imperial Navy on 6 December 1916 as SM UC-75.[1] In 13 patrols UC-75 was credited with sinking 59 ships, either by torpedo or by mines laid. UC-75 rammed and sunk by on 31 May 1918 with 17 dead and 14 survivors. HMS Fairy had sustained heavy damage and sank a short time later.
A Type UC II submarine, UC-75 had a displacement of 410t when at the surface and 493t while submerged. She had a length overall of 50.45m (165.52feet), a beam of 5.22m (17.13feet), and a draught of 3.650NaN0. The submarine was powered by two six-cylinder four-stroke diesel engines each producing 290PS300PS (a total of 580PS600PS), two electric motors producing 620PS, and two propeller shafts. She had a dive time of 30 seconds and was capable of operating at a depth of .
The submarine had a maximum surface speed of and a submerged speed of . When submerged, she could operate for at ; when surfaced, she could travel at . UC-75 was fitted with six 100cm (00inches) mine tubes, eighteen UC 200 mines, three 50cm (20inches) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8sp=usNaNsp=us Uk L/30 deck gun. Her complement was twenty-six crew members.
| Date | Name | Nationality | Tonnage[2] | Fate[3] | |
|---|---|---|---|---|---|
| 25 March 1917 | Industria |  United Kingdom | 133 | Sunk | |
| 25 March 1917 | Marshall |  Norway | 1,123 | Sunk | |
| 25 March 1917 | Median | United Kingdom | 214 | Sunk | |
| 25 March 1917 | Rosslyn | United Kingdom | 113 | Sunk | |
| 28 March 1917 | Expedient | United Kingdom | 145 | Sunk | |
| 29 March 1917 | Schaldis |  Belgium | 1,241 | Sunk | |
| 1 May 1917 | Alide | 175 | Sunk | ||
| 3 May 1917 | Carberry King | United Kingdom | 31 | Sunk | |
| 3 May 1917 | Eleanor | United Kingdom | 31 | Sunk | |
| 3 May 1917 | Fastnet | United Kingdom | 31 | Sunk | |
| 3 May 1917 | Hibernia | United Kingdom | 21 | Sunk | |
| 3 May 1917 | Lucky Lass | United Kingdom | 10 | Sunk | |
| 3 May 1917 | North Star | United Kingdom | 15 | Sunk | |
| 3 May 1917 | Sir Edward Birkbeck | United Kingdom | 23 | Sunk | |
| 4 May 1917 | Marie |  France | 133 | Sunk | |
| 5 May 1917 | HMS Lavender | 1,200 | Sunk | ||
| 6 May 1917 | President | France | 354 | Sunk | |
| 15 May 1917 | Polymnia | United Kingdom | 2,426 | Sunk | |
| 7 June 1917 | Wilhelm | United Kingdom | 187 | Sunk | |
| 11 June 1917 | Anglian | United Kingdom | 5,532 | Sunk | |
| 12 June 1917 | HMS Prize | 199 | Damaged | ||
| 18 June 1917 | Kathlamba | United Kingdom | 6,382 | Damaged | |
| 19 June 1917 | Kelso | United Kingdom | 1,292 | Sunk | |
| 20 June 1917 | Benita | United Kingdom | 130 | Sunk | |
| 20 June 1917 | Bidartaise | France | 123 | Sunk | |
| 29 July 1917 | Saint Marcouf | France | 1,117 | Sunk | |
| 1 August 1917 | Karina | United Kingdom | 4,222 | Sunk | |
| 3 August 1917 | Beechpark | United Kingdom | 4,763 | Sunk | |
| 3 August 1917 | HMS Mary B. Mitchell | 227 | Damaged | ||
| 25 August 1917 | Cymrian | United Kingdom | 1,014 | Sunk | |
| 29 August 1917 | Cooroy | United Kingdom | 2,470 | Sunk | |
| 29 August 1917 | Lynburn | United Kingdom | 587 | Sunk | |
| 28 September 1917 | William Middleton | United Kingdom | 2,543 | Damaged | |
| 9 October 1917 | Main | United Kingdom | 715 | Sunk | |
| 12 October 1917 | W. M. Barkley | United Kingdom | 569 | Sunk | |
| 13 October 1917 | United Kingdom | 2,293 | Sunk | ||
| 19 October 1917 | Hazelwood | United Kingdom | 3,120 | Sunk | |
| 3 November 1917 | HMD Deliverer | 79 | Sunk | ||
| 3 November 1917 | Atlantian | United Kingdom | 9,399 | Damaged | |
| 4 November 1917 | Longwy | France | 2,315 | Sunk | |
| 8 November 1917 | The Marquis | United Kingdom | 373 | Sunk | |
| 1 December 1917 | Euphorbia | United Kingdom | 3,109 | Sunk | |
| 1 December 1917 | Rydal Hall | United Kingdom | 3,314 | Sunk | |
| 4 December 1917 | Milton | United Kingdom | 3,267 | Damaged | |
| 7 December 1917 | Earl Of Elgin | United Kingdom | 4,448 | Sunk | |
| 28 December 1917 | Alfred H. Read | United Kingdom | 457 | Sunk | |
| 28 December 1917 | Chirripo | United Kingdom | 4,050 | Sunk | |
| 3 January 1918 | Asborg | Norway | 2,750 | Sunk | |
| 4 January 1918 | Day Spring | United Kingdom | 39 | Sunk | |
| 4 January 1918 | Gratitude | United Kingdom | 40 | Sunk | |
| 4 January 1918 | Varuna | United Kingdom | 40 | Sunk | |
| 5 January 1918 | Iolanthe | United Kingdom | 3,081 | Sunk | |
| 6 January 1918 | Arca | United Kingdom | 4,839 | Damaged | |
| 7 January 1918 | Gascony | United Kingdom | 3,133 | Sunk | |
| 7 January 1918 | Leon | France | 2,401 | Sunk | |
| 5 March 1918 | Edouard Marie | Belgium | 32 | Sunk | |
| 9 March 1918 | Marguerite | United Kingdom | 10 | Sunk | |
| 10 March 1918 | Sunrise | United Kingdom | 56 | Sunk | |
| 10 March 1918 | Wave | United Kingdom | 47 | Sunk | |
| 13 March 1918 | Arno Mendi |  Spain | 2,827 | Sunk | |
| 14 March 1918 | Tweed | United Kingdom | 1,777 | Sunk | |
| 17 March 1918 | Eliza Anne | United Kingdom | 36 | Sunk | |
| 18 March 1918 | Navigator | United Kingdom | 3,803 | Damaged | |
| 28 March 1918 | Dryden | United Kingdom | 5,839 | Damaged | |
| 16 April 1918 | Hungerford | United Kingdom | 5,811 | Sunk | |
| 19 April 1918 | War Helmet | United Kingdom | 8,184 | Sunk | |
| 12 May 1918 | Benlawers | United Kingdom | 3,949 | Damaged | |
| 29 May 1918 | HMT Dirk | 181 | Sunk | ||
| 31 May 1918 | 355 | Sunk |