{"id":"atlantic-blockade","title":"Blockade and the U-boat war, 1914-1918","kind":"sea","bbox":[[-78,7],[11,68]],"minZoom":0.2,"dates":["1914-08-04","1918-11-11"],"sections":["world/economic-war","sea-air/blockade","sea-air/u-boats","1915/uboats-air","1917/uboat-gamble"],"views":{"world/economic-war":{"date":"1917-09-15","center":[-30,46],"zoom":0.8,"compact":{"center":[-26,47],"zoom":0.6}},"sea-air/blockade":{"date":"1915-03-11","center":[-4,59.5],"zoom":2.7},"sea-air/u-boats":{"date":"1917-04-15","center":[-10,51.5],"zoom":2.1},"1915/uboats-air":{"date":"1915-05-07","center":[-8.95,51.45],"zoom":5.6},"1917/uboat-gamble":{"date":"1917-05-10","center":[-9,47.5],"zoom":1}},"features":[{"type":"line","id":"zone-1917-02-limit","label":"Barred zone, 1 Feb 1917","side":"central","style":"boundary","from":"1917-02-01","to":"1917-11-21","coords":[[2.94435,51.53344],[2.97519,51.69504],[3.66224,52.14192],[4.14417,52.62421],[4.27858,53.12547],[4.47168,53.42388],[4.87124,53.60718],[4.87124,59.30686],[0,62],[-5,62],[-6.67864,61.3432],[-10,62],[-15,61],[-20,57],[-20,47],[-15,43],[-9.69874,43],[-7.86806,44.10533],[-7.68778,44.12339],[-5.84993,43.9836],[-3.78611,43.82422],[-2.7526,43.78721],[-1.79194,43.70589],[-1.79194,43.37278]],"note":"From 1 February 1917 German submarines were to sink without warning every ship, neutral or enemy, met inside this line round Britain and France."},{"type":"line","id":"zone-1917-11-limit","label":"Barred zone extended, Nov 1917","side":"central","style":"boundary","from":"1917-11-22","to":"1918-11-11","coords":[[3.36911,51.36696],[2.95,51.58333],[3.86667,52.03333],[4.36667,52.46667],[4.41667,52.66667],[3.66667,52.66667],[3.66667,54.75],[4,55.16667],[4,56],[4.83333,56],[4.83336,59.14144],[4.74207,59.15397],[4.66158,59.17941],[4.59865,59.2156],[4.55862,59.25953],[4.54494,59.30748],[4.5589,59.35542],[4.59941,59.39927],[4.66312,59.4353],[0,62],[-5,62],[-6.67864,61.3432],[-10,62],[-15,61],[-30,57],[-30,47],[-15,43],[-9.69874,43],[-7.86806,44.10533],[-7.68778,44.12339],[-5.84993,43.9836],[-3.78611,43.82422],[-2.7526,43.78721],[-1.79194,43.70589],[-1.79194,43.37278]],"note":"From 22 November 1917 the barred zone reached out to 30 degrees West and a new zone was declared round the Azores, while a strip off the Dutch coast was to be released from 1 January 1918."},{"type":"line","id":"zone-azores-1917","label":"Azores barred zone, Nov 1917","side":"central","style":"boundary","from":"1917-11-22","to":"1918-01-10","coords":[[-17,39],[-27.75,44],[-34,44],[-37,42.5],[-37,37],[-26,30],[-20,34],[-17,39]],"note":"From 22 November 1917 Germany declared the waters round the Azores, an Allied base, a barred zone in which ships would be sunk without warning."},{"type":"line","id":"zone-azores-1918","label":"Azores barred zone, Jan 1918","side":"central","style":"boundary","from":"1918-01-11","to":"1918-11-11","coords":[[-27.75,44],[-34,44],[-37,42.5],[-37,37],[-26,30],[-17,30],[-12,34],[-12,36.75],[-27.75,44]],"note":"From 11 January 1918 the barred zone round the Azores was carried east past Madeira, which Germany named an enemy base."},{"type":"line","id":"np-1915-01-a","label":"Northern Patrol line A","side":"allied","style":"fortline","from":"1915-01-19","to":"1915-04-06","coords":[[-10,62.33333],[-10,62.99955],[-10,63.66577]],"note":"From 19 January 1915 the armed merchant cruisers of the 10th Cruiser Squadron patrolled east and west across this 80-mile centre line, stopping ships bound for Germany."},{"type":"line","id":"np-1915-01-b","label":"Northern Patrol line B","side":"allied","style":"fortline","from":"1915-01-19","to":"1915-04-06","coords":[[1.25,61.16667],[1.25,61.83288],[1.25,62.4991]],"note":"From 19 January 1915 the armed merchant cruisers of the 10th Cruiser Squadron patrolled east and west across this 80-mile centre line, stopping ships bound for Germany."},{"type":"line","id":"np-1915-01-c","label":"Northern Patrol line C","side":"allied","style":"fortline","from":"1915-01-19","to":"1915-04-06","coords":[[-9,59.66667],[-9,60.33288],[-9,60.9991]],"note":"From 19 January 1915 the armed merchant cruisers of the 10th Cruiser Squadron patrolled east and west across this 80-mile centre line, stopping ships bound for Germany."},{"type":"line","id":"np-1915-01-d","label":"Northern Patrol line D","side":"allied","style":"fortline","from":"1915-01-19","to":"1915-04-06","coords":[[-8.5875,57.815],[-9.1251,58.41768],[-9.68138,59.01803]],"note":"From 19 January 1915 the armed merchant cruisers of the 10th Cruiser Squadron patrolled east and west across this 80-mile centre line, stopping ships bound for Germany."},{"type":"line","id":"np-1915-04-c","label":"Northern Patrol, area C","side":"allied","style":"fortline","from":"1915-04-07","to":"1916-04-16","coords":[[-6.67864,61.3932],[-8,58.5]],"note":"From 7 April 1915 the centre line of patrol area C ran from Cape Sydero in the Faroes to 58°30'N, 8°W."},{"type":"line","id":"np-1915-04-g","label":"Northern Patrol, area G","side":"allied","style":"fortline","from":"1915-04-07","to":"1916-04-16","coords":[[3,62],[3,62.75],[3,63.5]],"note":"From 7 April 1915 the centre of patrol area G was the meridian of 3 degrees East between 62 and 63 1/2 degrees North."},{"type":"line","id":"np-1916-04","label":"Northern Patrol line, Apr 1916","side":"allied","style":"fortline","from":"1916-04-17","to":"1916-11-28","coords":[[-11.5,56.5],[-12.625,58.25],[-13.75,60],[-14.875,61.75],[-16,63.5]],"note":"From 17 April 1916 the A and C patrols formed one line from west of the Hebrides towards Iceland, the cruisers 40 miles apart."},{"type":"line","id":"barrage-1918","label":"North Sea Mine Barrage","side":"allied","style":"minefield","from":"1918-06-07","to":"1918-11-11","coords":[[4.9125,60],[3.16667,60.35],[-0.83333,59.33333],[-2.08333,59.33333],[-2.45,58.83333],[-0.83333,58.83333],[3.16667,59.48333],[4.81667,59.20833],[4.9125,60]],"note":"British minelayers began this barrage in March 1918 and American ones in June; by the Armistice some 73,000 mines lay between Norwegian waters and Orkney."},{"type":"line","id":"approach-a","label":"Approach A","side":"allied","style":"boundary","from":"1917-02-01","to":"1917-07-31","coords":[[-5.64282,50.14138],[-18.05954,47.69685],[-18.03135,44.34262],[-5.78547,49.71203]],"note":"In early 1917 Approach A, one of four areas that were shifted from time to time, gathered the traffic bound for the western entrance of the English Channel."},{"type":"line","id":"approach-b","label":"Approach B","side":"allied","style":"boundary","from":"1917-02-01","to":"1917-07-31","coords":[[-10.3189,51.975],[-13.40532,52.97052],[-18.13514,52.93457],[-18.15328,49.98925],[-13.3629,49.98927],[-10.03056,51.29305]],"note":"In early 1917 Approach B, one of four areas that were shifted from time to time, gathered the traffic bound for the south of Ireland."},{"type":"line","id":"approach-c","label":"Approach C","side":"allied","style":"boundary","from":"1917-02-01","to":"1917-07-31","coords":[[-7.94908,55.39985],[-18.07646,55.41441],[-18.13514,52.93457],[-13.40532,52.97052],[-8.53288,54.70702]],"note":"In early 1917 Approach C, one of four areas that were shifted from time to time, gathered the traffic bound for the north of Ireland."},{"type":"line","id":"approach-d","label":"Approach D","side":"allied","style":"boundary","from":"1917-02-01","to":"1917-07-31","coords":[[-4.05375,60.19048],[-7.24501,60.9482],[-18.0258,61.00011],[-18.11806,57.4172],[-5.18149,59.35319]],"note":"In early 1917 Approach D, one of four areas that were shifted from time to time, gathered the traffic bound for the east coast ports by way of the north of Scotland."},{"type":"route","id":"route-approach-a1","label":"Typical route for A","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-19.33845,37.2429],[-16.55756,45.81723],[-5.97725,49.97993]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-a2","label":"Typical route for A","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-22.96173,37.26759],[-18.03009,47.10168],[-5.94496,49.98541]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-b1","label":"Typical route for B","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.3965,47.4363],[-16.01728,52.32629],[-10.13829,51.82569]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-b2","label":"Typical route for B","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.43831,44.44154],[-13.91007,51.36748],[-9.8068,51.34068]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-b3","label":"Typical route for B","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.46472,42.80002],[-13.7257,50.3829],[-9.81974,51.33532]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-c1","label":"Typical route for C","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.28882,52.87959],[-18.0287,54.62327],[-7.96434,55.37391]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-c2","label":"Typical route for C","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.316,52.28825],[-17.88152,53.10105],[-14.06045,53.15827],[-7.56173,55.43096]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-d1","label":"Typical route for D","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.23555,57.21349],[-13.71094,59.73526],[-9.20383,59.77734],[-2.11175,59.69418]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-approach-d2","label":"Typical route for D","side":"allied","style":"fleet","from":"1917-02-01","to":"1917-07-31","coords":[[-30.31529,51.92492],[-14.86406,58.48659],[-5.60574,59.53635],[-2.19551,59.45699]],"note":"In early 1917 merchant ships sailed singly along routes like this into the approach areas, where the few patrol craft gave little protection and losses were heavy."},{"type":"route","id":"route-lusitania","label":"Lusitania, 7 May 1915","side":"allied","style":"fleet","from":"1915-05-07","to":"1915-05-07","coords":[[-9.54853,51.31216],[-9.22922,51.30213],[-8.78783,51.4201],[-8.54778,51.4125]],"times":[{"at":1,"time":"12:40"},{"at":2,"time":"13:40"},{"at":3,"time":"14:10"}],"note":"Bound from New York for Liverpool at 18 knots, the Lusitania closed the Irish coast at 12:40 to fix her position on the Old Head of Kinsale, then turned back east at 13:40."},{"type":"point","id":"pt-lusitania","label":"Lusitania sunk","symbol":"sinking","side":"allied","at":[-8.54778,51.4125],"time":"14:10","from":"1915-05-07","to":"1918-11-11","note":"At 14:10 on 7 May 1915 a single torpedo from U-20 hit the Lusitania about 11 miles off the Old Head of Kinsale; she sank in 18 minutes and 1,198 people died."},{"type":"point","id":"pt-pathfinder","label":"HMS Pathfinder sunk","symbol":"sinking","side":"allied","at":[-2.15417,56.1225],"from":"1914-09-05","to":"1918-11-11","note":"On 5 September 1914 U-21 sank the cruiser Pathfinder off the Firth of Forth, the first ship sunk by a self-propelled torpedo fired from a submarine."},{"type":"point","id":"pt-falaba","label":"Falaba sunk","symbol":"sinking","side":"allied","at":[-6.6,51.5],"from":"1915-03-28","to":"1918-11-11","note":"On 28 March 1915 U-28 torpedoed the liner Falaba while her passengers were still taking to the boats; one American was among the dead."},{"type":"point","id":"pt-arabic","label":"Arabic sunk","symbol":"sinking","side":"allied","at":[-8.53333,50.83333],"from":"1915-08-19","to":"1918-11-11","note":"On 19 August 1915 U-24 sank the outward-bound White Star liner Arabic without warning; Americans were among the dead, and Germany then promised to spare liners."},{"type":"point","id":"pt-u27","label":"U-27 sunk by Baralong","symbol":"sinking","side":"central","at":[-7.36667,50.71667],"from":"1915-08-19","to":"1918-11-11","note":"On 19 August 1915 the Q-ship Baralong sank U-27; the killing of her surviving crew became the notorious Baralong incident."},{"type":"point","id":"pt-sussex","label":"Sussex torpedoed","symbol":"explosion","side":"allied","at":[0.96667,50.70018],"time":"14:50","from":"1916-03-24","to":"1918-11-11","note":"At about 14:50 on 24 March 1916 UB-29 torpedoed the Channel steamer Sussex, bound from Folkestone for Dieppe, without warning; dozens died and the American protest led to the Sussex pledge."},{"type":"point","id":"pt-swarbacks-minn","label":"Northern Patrol anchorage","symbol":"hq","side":"allied","at":[-1.45,60.343],"from":"1915-06-18","to":"1917-11-29","note":"From mid-1915 the 10th Cruiser Squadron, the Northern Patrol, used the anchorage of Swarbacks Minn in Shetland as its advanced coaling base."},{"type":"point","id":"pt-convoy-harwich","label":"Dutch convoy, Harwich","symbol":"station","side":"allied","at":[1.28833,51.94444],"from":"1916-07-26","to":"1918-11-11","note":"From 26 July 1916 escorted convoys ran between the Hook of Holland and Harwich, the \"Beef Trip\" bringing Dutch food to Britain."},{"type":"point","id":"pt-convoy-lerwick","label":"Scandinavian convoys, Lerwick","symbol":"station","side":"allied","at":[-1.14861,60.15417],"from":"1917-04-29","to":"1918-11-11","note":"From 29 April 1917 regular convoys ran between Norway and Lerwick, the junction of the Scandinavian and east coast convoys."},{"type":"point","id":"pt-convoy-gibraltar","label":"Convoys from Gibraltar","symbol":"station","side":"allied","at":[-5.35,36.14],"from":"1917-05-10","to":"1918-11-11","note":"The first experimental convoy, of seventeen ships, sailed from Gibraltar on 10 May 1917 and arrived without loss; regular Gibraltar convoys followed from 26 July."},{"type":"point","id":"pt-convoy-hampton-roads","label":"Convoys from Hampton Roads","symbol":"station","side":"allied","at":[-76.4,36.95],"from":"1917-05-24","to":"1918-11-11","note":"The first experimental transatlantic convoy, of twelve ships, left Hampton Roads on 24 May 1917; a regular series every four days began on 2 July."},{"type":"point","id":"pt-convoy-sydney","label":"Convoys from Sydney, C.B.","symbol":"station","side":"allied","at":[-60.1829,46.1378],"from":"1917-07-10","to":"1918-11-11","note":"The first convoy of the Cape Breton series left Sydney on 10 July 1917."},{"type":"point","id":"pt-convoy-new-york","label":"Convoys from New York","symbol":"station","side":"allied","at":[-74.00611,40.71278],"from":"1917-07-14","to":"1918-11-11","note":"The first New York convoy sailed on 14 July 1917."},{"type":"point","id":"pt-convoy-halifax","label":"Convoys from Halifax","symbol":"station","side":"allied","at":[-63.57139,44.64778],"from":"1917-09-05","to":"1918-11-11","note":"The first regular Halifax convoy, of five Canadian troopships and seven merchantmen, sailed on 5 September 1917; one followed every eight days."},{"type":"point","id":"pt-convoy-sierra-leone","label":"Convoys from Sierra Leone","symbol":"station","side":"allied","at":[-13.23556,8.48722],"from":"1917-08-11","to":"1918-11-11","note":"The first convoy of faster ships from the South Atlantic sailed from Sierra Leone on 11 August 1917."},{"type":"point","id":"pt-convoy-dakar","label":"Convoys from Dakar","symbol":"station","side":"allied","at":[-17.432,14.67256],"from":"1917-08-22","to":"1918-11-11","note":"The first convoy from Dakar, for the South American, Cape and West African trades, sailed on 22 August 1917."},{"type":"point","id":"pt-convoy-lamlash","label":"Outward convoys, Lamlash","symbol":"station","side":"allied","at":[-5.1235,55.5373],"from":"1917-09-01","to":"1918-11-11","note":"By September 1917 ships from Liverpool and Glasgow bound for the Atlantic sailed in outward convoys from Lamlash."},{"type":"point","id":"pt-convoy-milford","label":"Outward convoys, Milford Haven","symbol":"station","side":"allied","at":[-5.04274,51.71418],"from":"1917-09-01","to":"1918-11-11","note":"By September 1917 slow outward convoys for Gibraltar and the south left Milford Haven."},{"type":"point","id":"pt-convoy-queenstown","label":"Outward convoys, Queenstown","symbol":"station","side":"allied","at":[-8.2967,51.851],"from":"1917-09-01","to":"1918-11-11","note":"By September 1917 faster outward ships from the Bristol Channel met for convoy at Queenstown, base of the British and American anti-submarine destroyers."},{"type":"point","id":"pt-convoy-falmouth","label":"Outward convoys, Falmouth","symbol":"station","side":"allied","at":[-5.06667,50.15],"from":"1917-09-01","to":"1918-11-11","note":"By September 1917 outward convoys left Falmouth every eight days for Gibraltar."},{"type":"point","id":"pt-convoy-plymouth","label":"Outward convoys, Plymouth","symbol":"station","side":"allied","at":[-4.14222,50.37139],"from":"1917-09-01","to":"1918-11-11","note":"By September 1917 the faster outward ships from the Channel and East Coast ports sailed in convoy from Plymouth every few days."},{"type":"label","id":"lbl-north-sea","text":"North Sea","style":"water","at":[3.6825,56.459]},{"type":"label","id":"lbl-north-atlantic","text":"North Atlantic Ocean","style":"water","at":[-33,47]},{"type":"label","id":"lbl-western-approaches","text":"Western Approaches","style":"region","at":[-20,53],"minZoom":2},{"type":"label","id":"lbl-bay-of-biscay","text":"Bay of Biscay","style":"water","at":[-4.4,45.5],"minZoom":2},{"type":"label","id":"lbl-english-channel","text":"English Channel","style":"water","at":[-2,50],"angle":-20,"minZoom":3},{"type":"label","id":"lbl-irish-sea","text":"Irish Sea","style":"water","at":[-5,53.5],"minZoom":3},{"type":"label","id":"lbl-celtic-sea","text":"Celtic Sea","style":"water","at":[-7.91444,50.50222],"minZoom":3},{"type":"label","id":"lbl-north-channel","text":"North Channel","style":"water","at":[-5.62194,55.0575],"angle":58,"minZoom":5},{"type":"label","id":"lbl-st-georges-channel","text":"St George's Channel","style":"water","at":[-6,52],"angle":-70,"minZoom":4},{"type":"label","id":"lbl-strait-of-dover","text":"Strait of Dover","style":"water","at":[1.45,51],"angle":-40,"minZoom":5},{"type":"label","id":"lbl-faroe-shetland","text":"Faroe-Shetland Channel","style":"water","at":[-3.63333,61.36667],"angle":-35,"minZoom":3},{"type":"label","id":"lbl-denmark-strait","text":"Denmark Strait","style":"water","at":[-24,67],"minZoom":2},{"type":"label","id":"lbl-skagerrak","text":"Skagerrak","style":"water","at":[9.07306,57.84722],"angle":-20,"minZoom":3},{"type":"label","id":"lbl-fair-isle-channel","text":"Fair Isle Channel","style":"water","at":[-1.75232,59.60526],"minZoom":5}],"sources":[{"url":"https://history.state.gov/historicaldocuments/frus1917Supp01v01/d92","used_for":"Limits of the barred zone of 1 February 1917 (German memorandum of 31 January 1917)"},{"url":"https://history.state.gov/historicaldocuments/frus1918Supp01v02/d861","used_for":"Azores zone carried east past Madeira from 11 January 1918 (German declaration of 5 January 1918)"},{"url":"https://history.state.gov/historicaldocuments/frus1915Supp/d125","used_for":"German war zone proclamation of 4 February 1915 (no seaward limit, hence no line)"},{"url":"https://archive.org/details/crisisofnavalwar00jellrich","used_for":"Jellicoe, The Crisis of the Naval War (1920): Chart A approach areas and typical routes (re-digitized), Chart C barred zones, convoy ports and sailing intervals"},{"url":"https://archive.org/details/grandfleet19141900jell","used_for":"Jellicoe, The Grand Fleet 1914-1916 (1919): Northern Patrol centre lines of 19 January 1915, 7 April 1915 and 17 April 1916"},{"url":"https://archive.org/details/seabornetrade03char","used_for":"Dates of the first convoys (Gibraltar, Hampton Roads, Sydney, New York, Sierra Leone, Dakar, Halifax) and outward ports of assembly, September 1917"},{"url":"https://en.wikipedia.org/wiki/North_Sea_Mine_Barrage","used_for":"Barrage areas A, B, C; 70,177 mines; thirteenth and last American excursion 26 October 1918"},{"url":"https://en.wikipedia.org/wiki/Northern_Patrol","used_for":"Northern Patrol base at Swarbacks Minn, disbandment 29 November 1917"},{"url":"https://en.wikipedia.org/wiki/Shetland","used_for":"10th Cruiser Squadron stationed at Swarbacks Minn"},{"url":"https://en.wikipedia.org/wiki/Convoys_in_World_War_I","used_for":"Holland convoy from 26 July 1916, Norwegian and Lerwick convoys from 29 April 1917, Gibraltar experimental convoy 10 May 1917 (its other first-convoy dates differ from Fayle, who is followed)"},{"url":"https://www.titanicinquiry.org/Lusitania/Report/Reptorp.php","used_for":"Lusitania courses, speed and times on 7 May 1915 (Mersey report)"},{"url":"https://en.wikipedia.org/wiki/RMS_Lusitania","used_for":"Wreck position of the Lusitania"},{"url":"https://en.wikipedia.org/wiki/Sinking_of_the_RMS_Lusitania","used_for":"Time of the torpedo (14:10), 11 miles off the Old Head of Kinsale, toll"},{"url":"https://en.wikipedia.org/wiki/HMS_Pathfinder_(1904)","used_for":"Position and time of the sinking of Pathfinder"},{"url":"https://en.wikipedia.org/wiki/SS_Falaba","used_for":"Position of the sinking of Falaba"},{"url":"https://en.wikipedia.org/wiki/SM_U-27_(Germany)","used_for":"Position of the sinking of U-27 by Baralong"},{"url":"https://en.wikipedia.org/wiki/Cobh","used_for":"Queenstown as the British and American destroyer base"},{"url":"https://www.wikidata.org/wiki/Q301633","used_for":"Akraberg, southern point of the Faroes (Cape Sydero)"},{"url":"https://www.wikidata.org/wiki/Q166479","used_for":"St Kilda, origin of Northern Patrol line D"},{"url":"https://api.deutsche-digitale-bibliothek.de/search/index/newspaper-issues/select?q=id:%22QG56FWCW775MUHWSIDKUV6TNF7YMDCSE-FILE_0003_ALTO_DDB_FULLTEXT%22","used_for":"Deutscher Reichsanzeiger, 22 November 1917: German declaration extending the barred zone from 22 November 1917 (limits round England, Azores zone, released Dutch strip)"},{"url":"https://api.deutsche-digitale-bibliothek.de/search/index/newspaper-issues/select?q=id:%22BVHJVITMES2HPOJ42NLR7YF3TZO6IWJN-ALTO9408419_DDB_FULLTEXT%22","used_for":"Koelnische Zeitung, 22 November 1917: full text of the North Sea and Azores limits of the November 1917 declaration"},{"url":"https://archive.org/details/northernbarrageo00unitrich","used_for":"The Northern Barrage and Other Mining Activities (US Navy, 1920): barrage area of 16 December 1918, first American excursion 7 June 1918, British laying from March 1918"},{"url":"https://www.openstreetmap.org/way/548013925","used_for":"Utsira (Udsire) lighthouse"},{"url":"https://www.openstreetmap.org/way/938083344","used_for":"Swarbacks Minn anchorage"},{"url":"https://www.wikidata.org/wiki/Q36856","used_for":"The Zwin, end of the Belgian-Dutch land frontier"},{"url":"https://uboat.net/wwi/ships_hit/4693.html","used_for":"Pathfinder position 56 07 N 2 09 W"},{"url":"https://uboat.net/wwi/ships_hit/399.html","used_for":"Arabic sunk 19 August 1915 at 50 50 N 8 32 W"},{"url":"https://en.wikipedia.org/wiki/SS_Arabic_(1902)","used_for":"Arabic sunk without warning 50 miles south of Kinsale; Americans among the dead; the Arabic pledge"},{"url":"https://history.state.gov/historicaldocuments/frus1916Supp","used_for":"Sussex: left Folkestone 13:25, torpedoed about 14:50 some 13 miles from Dungeness on a course almost due south (statement of facts, April 1916)"},{"url":"https://en.wikipedia.org/wiki/SS_Sussex","used_for":"Sussex torpedoed by UB-29 on 24 March 1916, at least 50 dead"},{"url":"https://www.wikidata.org/wiki/Q911577","used_for":"Dungeness"}]}