List of shipwrecks in October 1918

The list of shipwrecks in October 1918 includes ships sunk, foundered, grounded, or otherwise lost during October 1918.

1 October

 * SS Aldebaran (1883) (🇸🇪 Sweden): World War I: The cargo ship was torpedoed and sunk in the Atlantic Ocean 7 nmi off the Wolf Rock, Cornwall, United Kingdom (49.9°N, -5.98333°W) by SMU UB-112 with the loss of all nineteen crew.
 * SS Bylands (1899) ( undefined): World War I: The cargo ship was shelled and sunk in the Atlantic Ocean 150 nmi north north west of Cape Villano, Spain by SMU U-139 . Her crew survived.
 * SS Francoli (1865) (🇪🇸 Spain): World War I: The cargo ship was shelled and sunk in the Mediterranean Sea 14 nmi east of Cape Palos, Murcia by SMU UB-49 . Her fourteen crew were rescued by a French merchant vessel.
 * Giuseppino M. ( undefined): World War I: The sailing vessel was sunk in the Gulf of Salerno by SMU UC-53.
 * SS Gjertrud (🇳🇴 Norway): World War I: The coaster was sunk in the Atlantic Ocean 2 nmi west of The Lizard, Cornwall by SMU UB-112 with the loss of eleven of her crew.
 * SS Manin (1900) ( undefined): World War I: The cargo ship was sunk in the Atlantic Ocean 150 nmi north north west of Cape Villano by SMU U-139.
 * SS Montfort (1899) ( undefined): World War I: Convoy OD 128: The cargo ship was torpedoed and damaged in the Atlantic Ocean 170 nmi west south west of the Bishop Rock, Isles of Scilly (48°N, -10.33333°W) by SMU U-55 with the loss of five crew. She sank the next day.
 * San Giuseppe A. ( undefined): World War I: The sailing vessel was sunk in the Gulf of Salerno by SMU UC-53.
 * Thèrese et Marthe (🇫🇷 France): World War I: The fishing vessel was sunk in thr Bay of Biscay (46.6°N, -2.63333°W) by SMU U-91.

2 October

 * HMS Arca (1912) : World War I: The tanker was torpedoed and sunk in the Atlantic Ocean 40 nmi north west by west of Tory Island, County Donegal (55.75°N, -7.58333°W) by SMU U-118 with the loss of 52 crew.
 * Avé Marie Stella (🇫🇷 France): World War I: The fishing vessel was shelled and sunk in the Bay of Biscay (45.98333°N, -2.23333°W) by SMU U-91.
 * SS Bamse (1881) ( undefined): World War I: The cargo ship was torpedoed and sunk in the English Channel 5 nmi east of The Lizard, Cornwall by SMU UB-112 with the loss of eleven of her crew.
 * SS Keltier (🇧🇪 Belgium): World War I: The cargo ship was torpedoed and sunk in the Atlantic Ocean (46.26667°N, -9.86667°W) by SM U-55 . The crew took to the lifeboats but were not recovered.
 *  Maia (🇫🇷 France): World War I: The schooner was shelled and sunk in the Bay of Biscay (45.41667°N, -1.8°W) by SMU U-91 with the loss of two of her crew.
 * Marie Emmanuel (🇫🇷 France): World War I: The fishing vessel was shelled and sunk in the Bay of Biscay south of the Île d'Yeu, Finistère (46.55°N, -2.38333°W) by SMU U-91 with the loss of five of her crew.
 * SS Poljames (1872) ( undefined): World War I: The coaster was torpedoed and sunk in the English Channel 6 nmi south of The Lizard by SMU UB-112 with the loss of thirteen of her crew.
 * Rio Cavalo (🇵🇹 Portugal): World War I: The sailing vessel was sunk in the Atlantic Ocean 290 nmi off Cape Prior, Spain by SMU U-139.
 * SMS Z : World War I: The barracks ship was scuttled at Bruges, West Flanders, Belgium.

3 October

 * SS Alberto Treves (1900) ( undefined): World War I: The cargo ship was sunk in the Atlantic Ocean 300 nmi off the coast of the United States by SMU U-155.
 * SS Ariel (1902) ( undefined): World War I: Convoy BG 68: The cargo ship was torpedoed and sunk in the Mediterranean Sea 54 nmi north of Cape Ténès, Algeria (37.6°N, 1.13333°W) by SMU UB-105 . Her crew survived.
 * SS Atlantis (1906) (🇳🇴 Norway): World War I: The cargo ship was sunk in the English Channel 6 nmi south east of The Lizard, Cornwall, United Kingdom by SMU UB-112 with the loss of two of her crew.
 * Blasios (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Aegean Sea by SMU UC-23.
 * SS Burutu ( undefined): The ocean liner collided with another vessel and sank with heavy loss of life, at least 170 people were killed.
 * SS Eupion (1914) ( undefined): World War I: The tanker was torpedoed and sunk in the River Shannon by SMU UB-90 with the loss of eleven of her crew.
 * SMS G41 : World War I: The V25-class destroyer was scuttled at Bruges, West Flanders, Belgium.
 * USS Herman Frasch (ID-1617) : The collier collided with USS George G. Henry (ID-1560) in the Atlantic Ocean 110 nmi east of Cape Sable Island, Nova Scotia, Canada and sank with the loss of 24 of her 89 crew.
 * HMT Lustring : The naval trawler was lost on this date.
 * SMS M : World War I: The barracks ship was scuttled at Bruges.
 * SMS S33 (: World War I: The V25-class destroyer was torpedoed and sunk in the North Sea by HMS L11.
 * SMS S34 : World War I: The V25-class destroyer struck a mine and sank in the North Sea with the loss of 70 of her crew.
 * SS Saint Luc (1908) (🇫🇷 France): World War I: Convoy BG 68: The cargo ship was torpedoed and sunk in the Mediterranean Sea 48 nmi nort of Cape Ténès (37.71667°N, 1.58333°W) by SMU UB-105 with the loss of 29 of her crew.
 * SMS V74 : World War I: The V25-class destroyer was scuttled at Bruges.
 * SS Westwood (1907) ( undefined): World War I: The collier was torpedoed and sunk in the Atlantic Ocean 5 nmi south west of The Lizard by SMU UB-112 with the loss of a crew member.

4 October

 * HMT Coleus : The naval trawler was lost on this date.
 * SS Hirano Maru (1908) (🇯🇵 Japan): World War I: The passenger ship was sunk in the Atlantic Ocean 200 nmi south of Ireland by SMU UB-91 with the loss of 292 of the 320 people on board.
 *  Industrial ( undefined): World War I: The schooner was scuttled in the Atlantic Ocean 250 nmi south east of Nantucket Island, Massachusetts, United States (37.95°N, -66.68333°W) by SMU U-155 . Her crew survived.
 * Kassid Karim (🇪🇬 Egypt): World War I: The sailing vessel was shelled and sunk in the Mediterranean Sea 75 nmi north of Alexandria by an enemy submarine.
 * HMS L10 : World War I: The L-class submarine was sunk in the Heligoland Bight by SMS V28 and SMS V29 (both ) with the loss of all 38 crew.
 * SS Mercedes (1887) (🇪🇸 Spain): World War I: The cargo ship was sunk in the Atlantic Ocean off San Sebastián, Gipuzkoa (43.41667°N, -1.98333°W) by SMU U-91 . Her crew survived.
 * HMS M. J. Hedley : The Q-ship capsized and sank on this date.
 * SS Nanna (1900) (🇳🇴 Norway): World War I: The cargo ship was sunk in the Atlantic Ocean 10 nmi west north west of The Lizard, Cornwall, United Kingdom by SMU UB-112 with the loss of nine of her crew.
 * SS San Saba (1879) (🇺🇸 United States): World War I: The cargo ship struck a mine and sank in the Atlantic Ocean off the Barnegat Lighthouse, New Jersey (39.66667°N, -73.91667°W) with the loss of 30 crew.
 * SS Oopack (1894) ( undefined): World War I: The cargo ship was torpedoed and sunk in the Mediterranean Sea 110 nmi east of Malta (35.93333°N, 16.33333°W) by SMU UB-68 . Her crew survived.
 * SMU UB-68 : World War I: The Type UB III submarine was shelled and sunk in the Mediterranean Sea (33.93333°N, 16.33333°W) with the loss of one of her 34 crew.
 *  Uranus (Flag of Russian SFSR.svg Russia: World War I: The brigantine was scuttled in the Atlantic Ocean south west of the Isles of Scilly, United Kingdom (46.7°N, -12.38333°W) by SMU U-55 . Her crew took to the lifeboats, but were not recovered.

5 October

 * SS Erindring (1901) ( undefined): World War I: The cargo ship was sunk in the Bay of Biscay (43.45°N, -2.4°W) by SMU U-91 with the loss of all 22 crew.
 * SS Gelderland ( undefined): World War I: The cargo ship was scuttled at Bruges, West Flanders, Belgium.
 * Hagios Marcos (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * SS Heathpark (1917) ( undefined): World War I: The cargo ship was sunk in the Bay of Biscay (43.45°N, -2.3°W) by SMU U-91 with the loss of all eighteen crew.
 *  Maria (🇪🇸 Spain): World War I: The schooner was torpedoed and sunk in the Gulf of Salonica.
 * SS Maria (1881) (🇪🇸 Spain): World War I: The cargo ship was sunk in the Gulf of Salonica (39.96667°N, 23.11667°W) by SMU UC-23 . Her crew survived.
 * Marigo (🇫🇷 France): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * USS Mary Alice (SP-397) : The patrol vessel was rammed and sunk in the Atlantic Ocean off Bridgeport, Connecticut by USS O-13 (SS-74) . Her crew were rescued by USS O-13.
 * SS Reventazon (1906) ( undefined): World War I: The cargo ship was torpedoed and sunk in the Gulf of Salonica 14 nmi west by south of Kassandra Point, Greece by SMU UC-23 with the loss of fifteen of her crew.
 * SS Rio Pardo (1905) ( undefined): World War I: The cargo ship was scuttled at Bruges.
 * SMS T122 : World War I: The S90-class torpedo boat struck a mine and sank in the North Sea with the loss of twelve of her crew.
 * SMU UB-10 : World War I: The Type UB I submarine was scuttled in the North Sea off Zeebrugge, West Flanders, Belgium (51.35°N, 3.2°W).
 * SMU UB-40 : World War I: The Type UB II submarine was scuttled in the North Sea off Ostend, West Flanders, Belgium.
 * SMU UB-59 : World War I: The Type UB III submarine was scuttled in the North Sea off Zeebrugge (51.31667°N, 3.2°W).
 * SMU UC-4 : World War I: The Type UC I submarine was scuttled in the North Sea off the coast of West Flanders (51.36667°N, 3.2°W).

6 October

 * HMS C12 : The C-class submarine collided with a destroyer in the Humber Estuary and sank. She was subsequently raised, repaired and returned to service.
 * HMS Otranto : The armed merchant cruiser collided with HMS Kashmir (1915) in the Atlantic Ocean north east of Ireland and was holed. She was driven ashore and wrecked with the loss of 431 lives.

7 October

 * HMT Kalmia : The naval trawler was lost in the Mediterranean Sea on this date.
 * SS Madeira (1897) (🇵🇹 Portugal): World War I: The cargo ship was sunk in the Mediterranean Sea off San Pietro Island, Italy by SMU UB-105 . Her crew survived.
 * HMT Ocean Foam : The naval trawler was lost on this date.
 * SS Saint Barnabe (1912) (🇫🇷 France): World War I: The cagro ship was sunk in the Mediterranean Sea 38 nmi east of San Pietro Island by SMU UB-105.
 * USS West Gate (ID-3216) : The cargo ship collided with USS American (ID-2292) in the Atlantic Ocean 250 nmi south east of Halifax, Nova Scotia, Canada and sank with the loss of seven crew.

8 October

 * SS Cazengo (1889) (🇵🇹 Portugal): World War I: The cargo ship was sunk in the Bay of Biscay off Saint-Jean-de-Luz, Pyrénées-Atlantiques, France (44.26667°N, -1.33333°W) by SMU U-91 . Her crew survived.
 *  Hawanee ( undefined): World War I: The schooner was scuttled in the Atlantic Ocean 350 nmi off Cape Finisterre, Spain (42.91667°N, -7.68333°W) by SMU U-157 . Her crew survived.
 * SS Thalia (1916) ( undefined): World War I: The cargo ship was torpedoed and sunk in the North Sea 4 nmi east south east of Filey, Yorkshire by SMU UC-17 with the loss of three of her crew.

9 October

 *  Pierre (🇫🇷 France): World War I: The three-masted schooner was shelled and sunk in the Bay of Biscay (43.81667°N, -1.56667°W) by SMU U-91 . Her crew survived.

10 October

 * André 🇫🇷 France): World War I: The sailing vessel was shelled and sunk in the Atlantic Ocean west of the Isles of Scilly, United Kingdom by SMU U-55.
 * RMS Leinster ( undefined): World War I: The troopship was torpedoed and sunk in the Irish Sea (53.31667°N, -5.78333°W) by SMU UB-123 with the loss of 523 lives. Survivors were rescued by HMY Helga, HMS Lively (1900), HMS Mallard (1896), HMS Seal (1897) (all ).

11 October

 * SS Luksefjell (1889) (🇳🇴 Norway): World War I: The cargo ship was sunk in the Bay of Biscay 8 nmi west north west of Capbreton, Landes, France (43.68333°N, -1.61667°W) by SMU U-91 with the loss of seven of her crew.
 * SS Maja (1883) (🇸🇪 Sweden): World War I: The cargo ship was sunk in the Irish Sea 15 nmi east of Ardglass, County Down, United Kingdom by SMU UB-126 with the loss of nine of her crew.

12 October

 * USAT Amphion : World War I: The troopship was shelled and damaged in the Atlantic Ocean (36.1°N, -62.98333°W) by SMU U-155 . with the loss of two of her crew.
 * SS Laila (1890) (🇳🇴 Norway): World War I: The cargo ship was torpedoed and sunk in the Irish Sea 6.5 nmi north of the Mull of Galloway, Wigtownshire, United Kingdom by SMU UB-126 with the loss of seventeen of her crew
 * Ohio ( undefined): The cargo ship collided with another vessel and sank in the English Channel. All 21 people on board were rescued by a Royal Navy destroyer.
 * SS Tripoli II (1880) ( undefined): World War I: The cargo ship was sunk in the Mediterranean Sea 20 nmi off Cape Passero, Sicily by SMU UB-105.

13 October

 * Aghion Spiridon (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Aghios Georgios (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Bioletta (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Evangelistria (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Evangelistrios (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Glaros (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.
 * Hamidieh (🇪🇬 Egypt): World War I: the sailing vessel was shelled and sunk in the Mediterranean Sea 50 nmi north west of Alexandria by and enemy submarine.
 * Iphigenia (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23 . Her crew survived.
 * Panaghia (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23 . Her crew survived.
 * Urania (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica by SMU UC-23.

14 October

 * PORTUGUESE TRAWLER Augusto de Castilho : World War I: The naval trawler was sunk in the Atlantic Ocean 100 nmi south west of the Azores by SMU U-139.
 * Bayard (🇫🇷 France): World War I: The fishing vessel was sunk in the Bay of Biscay (47.5°N, -4°W) by SMU U-91.
 * SS Dundalk (1899) ( undefined): World War I: The passenger ship was torpedoed and sunk in the Irish Sea 5 nmi north north west of The Skerries, Isle of Anglesey by SMU U-90 with the loss of 21 lives.
 *  Stifinder (🇳🇴 Norway): World War I: The barque was scuttled in the Atlantic Ocean (37.7°N, -53.68333°W) by SMU U-152 . Her crew survived.

15 October

 * Bretagne (🇫🇷 France): World War I: The sailing vessel was sunk in the Atlantic Ocean by SMU U-43 (Germany) . Her crew survived.
 * HM CMB-71A : The Coastal Motor Boat was lost on this date.
 * Evangelistria (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica (38.65°N, 25.21667°W) by SMU UC-23.
 * Georgios (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica (38.7°N, 25.35°W) by SMU UC-23.
 * HMS J6 : World War I: The J-class submarine was shelled and sunk in the North Sea off the coast of Northumberland by the Q-ship HMS Cymric, which mistook her pennant number J6 for U6 and assumed she was a U-boat. Fifteen of her 45 crew were lost.
 * Maria (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Gulf of Salonica (38.7°N, 25.35°W) by SMU UC-23 . Her crew survived.

16 October

 * SS Dumaru (🇺🇸 United States): The cargo ship was struck by lightning, caught fire and sank in the Pacific Ocean off Guam whilst on her maiden voyage.
 * SS Pentwyn (1910) ( undefined): World War I: The cargo ship was torpedoed and sunk in the Irish Sea 20 nmi north east by north of the Smalls Lighthouse by SMU U-90 with the loss of a crew member.
 * SMU UB-90 : World War I: The Type UB III submarine was torpedoed and sunk in the Skagerrak (57.91667°N, 10.45°W) by HMS L12 with the loss of all 38 crew.
 * SS War Council ( undefined): World War I: The cargo ship was torpedoed and sunk in the Mediterranean Sea 85 nmi west south west of Cape Matapan, Greece (35.73333°N, 20.26667°W) by SMU U-63 (Germany) . Her crew survived.

17 October

 * SS Bonvilston (1893) ( undefined): World War I: The cargo ship was torpedoed and sunk in the Irish Sea 9.5 nmi north west by west of Corsewall Point, Wigtownshire by SMU UB-92 . Her crew survived.
 * SS Lucia (1912) (🇺🇸 United States): World War I: The cargo ship was torpedoed and sunk in the Atlantic Ocean 1200 nmi off the coast of the United States (38.83333°N, -50.83333°W) by SMU U-155 with the loss of four of her crew.

18 October

 * HMS E3 : World War I: The E-class submarine was torpedoed and sunk in the North Sea off the mouth of the Ems by SMU U-27 (Germany) with the loss of all 28 of her crew.
 * SS Hunsdon (1911) ( undefined): World War I: The cargo ship was torpedoed and sunk in the Irish Sea (54.31667°N, -5.45°W) by SMU UB-94 with the loss of a crew member.
 * RFA Industry : World War I: The cargo ship was sunk in the Irish Sea by SMU UB-92 with the loss of 21 of her crew.
 * Njordur (🇩🇰 Iceland): World War I: The trawler was sunk in the Atlantic Ocean (57.03333°N, -10.96667°W) by SMU U-122.
 * ST Oceana ( undefined: The Admiralty tug was run into and sunk in Scapa Flow, Orkney Islands by ST Stobo Castle ( undefined).
 * SMU U-34 (Germany) : World War I: The Type U 31 submarine departed on patrol. Subsequently sunk off Gibraltar on or before 9 November with the loss of all 38 crew.
 * FRENCH BATTLESHIP Voltaire : World War I: The was torpedoed and damaged in the Aegean Sea of Milos, Greece by SMU UB-48.

19 October

 * Aida (🇵🇹 Portugal): World War I: The sailing vessel was sunk in the Atlantic Ocean off Brest, Finistère, France by SMU U-43 (Germany) . Her crew survived.
 * SS Almerian (1897) ( undefined): World War I: The cargo ship struck a mine and sank in the Mediterranean Sea 13 nmi off Licata, Sicily (37.18333°N, 13.65°W). Her crew survived.
 * HMS Plumpton : World War I: The Racecourse-class minesweeper struck a mine and was damaged in the North Sea off Ostend, West Flanders, Belgium. She was beached but was declared a total loss.
 * SMU UB-123 : World War I: The Type UB III submarine struck a mine and sank in the North Sea with the loss of all 36 crew.

20 October

 *  Emily Millington ( undefined): World War I: The schooner was shelled and sunk in the Atlantic Ocean 13 nmi north north east of the Bishop Rock, Isles of Scilly by SMU UB-92 . Her crew survived.
 * HMS M21 : World War I: The M15-class monitor struck a mine in the North Sea off Ostend, West Flanders, Belgium. She was taken in tow but sank in the English Channel off Dover, Kent.

21 October

 * USS Cero (SP-1189) : The patrol vessel was destroyed by fire in Narragansett Bay. Her crew were rescued.
 * SS Saint Barchan (1917) ( undefined): World War I: The coaster was torpedoed and sunk in the Irish Sea 4 nmi off St. John's Point, County Down by SMU UB-94 with the loss of eight of her crew.
 * HMML 561 : The motor launch was lost on this date.
 * Moscow ( undefined): Russian Revolution: The cargo ship was scuttled at Petrograd to prevent her capture by Bolshevik forces.
 * SMU UB-89 : The Type UB III submarine collided with SMS Frankfurt ( at Kiel, Schleswig-Holstein (54.35°N, 10.16667°W) and sank with the loss of seven lives. She was raised on 30 October.

23 October

 * Aghios Gerasimos (🇬🇷 Greece): World War I: The sailing vessel was sunk in the Mediterranean Sea south of Crete (34°N, 25.51667°W) by SMU UC-74.

25 October

 * SS Princess Sophia (🇨🇦 Canada): The passenger ship grounded on the Vanderbilt Reef near Juneau, Alaska and sank with loss of 343 lives.

27 October

 * HMT Calceolaria : World War I: The naval trawler struck a mine and sank in the North Sea off the Elbow Lightship ( undefined) (51.43333°N, 1.6°W) with the loss of five of her crew.
 * SS Chaparra (1906) (🇨🇺 Cuba): World War I: The cargo ship struck a mine and sank in the Atlantic Ocean 70 nmi south east of the Barnegat Lighthouse, New Jersey, United States with the loss of six of her crew.
 * HMS George R. Gray (: The tug was lost on this date.
 *  Maria Emilia (🇵🇹 Portugal): The barque sprang a leak in the Atlantic Ocean (30.33333°N, -66.2°W) and was abandoned by her crew. They were rescued by SS Themistocles (🇬🇷 Greece).
 * HMT Neptunian : The naval trawler collided with another vessel and sank in the Atlantic Ocean off Rathlin Island, County Donegal.
 * SMU U-78 : World War I: The Type UE I submarine was torpedoed and sunk in the Skagerrak (56.03333°N, 5.13333°W) by HMS G2 with the loss of all 40 crew.

28 October

 * SS Maj (🇸🇪 Sweden): The cargo ship ran aground at Haar-om-Jaederen. She was declared a total loss on 2 November.
 * USS Tarantula (SP-124) : The patrol boat collided with SS Frisia (🇳🇱 Netherlands) in the Atlantic Ocean 8 nmi off the Fire Island Lightship and sank.
 * SMU U-47 (Germany) : World War I: The Type U 43 submarine was scuttled at Pula, Austria-Hungary (44.86667°N, 13.83333°W).
 * SMU U-65 (Germany) : World War I: The Type U 63 submarine was scuttled at Pula (44.86667°N, 13.83333°W).
 * SMU UB-48 : World War I: The Type UB II submarine was scuttled at Pula (44.86667°N, 13.83333°W).
 * SMU UB-116 : World War I: The Type UB III submarine struck a mine and was then depth charged and sunk off the Orkney Islands, United Kingdom with the loss of all 36 crew.
 * SMU UC-25 : World War I: The Type UC II submarine was scuttled at Pula (44.86667°N, 13.83333°W).
 * SMU UC-53 : World War I: The Type UC II submarine was scuttled at Pula (44.86667°N, 13.83333°W).
 * SMU UC-54 : World War I: The Type UC II submarine was scuttled at Trieste, Italy (45.65°N, 13.75°W).

29 October

 * SMS A51 : World War I: The A26-class torpedo boat was scuttled at Rijeka, Kingdom of Serbs, Croats, and Slovenes.
 * SMS A82 : World War I: The A56-class torpedo boat was scuttled at Rijeka.
 * HMT Falkirk : The naval trawler was lost on this date.
 * HMT Thomas Cornwall : The Mersey-class trawler collided with another vessel and sank in the North Sea off Filey, Yorkshire with the loss of twenty of her crew.
 * HMS Ulysses (1917) : The R-class destroyer collided with SS Ellerie ( undefined) and sank in the Firth of Clyde.

30 October

 * SMU U-73 : World War I: The Type UE I submarine was scuttled at Kotor,  State of Slovenes, Croats and Serbs (44.86667°N, 13.83333°W).
 * SMU UC-34 : World War I: The Type UC II submarine was scuttled at Pula, Austria-Hungary (44.86667°N, 13.83333°W).

31 October

 * SS A. J. Fuller (🇺🇸 United States): The cargo ship was rammed and sunk in Elliott Bay by a Japanese merchant vessel.
 * SMU UB-129 : World War I: The Type UB III submarine was scuttled at Rijeka, State of Slovenes, Croats and Serbs (45.31667°N, 14.43333°W).

Unknown date

 * SMS Brugge : World War I: The depôt ship was scuttled at Zeebrugge, West Flanders, Belgium.
 * HMS G7 : World War I: The G-class submarine was lost in the North Sea on or after 23 October. She was declared lost on 1 November.