Editing Scapa Flow (section)

====Base for the British Grand Fleet====

Historically, the main British naval bases were near the [[English Channel]] to counter the continental naval powers: the Dutch Republic, France, and Spain.

In 1904, in response to the build-up of the German ''[[Kaiserliche Marine]]'''s [[High Seas Fleet]], Britain decided that a northern base was needed to control the entrances to the [[North Sea]], as part of a revised policy of 'distant' rather than 'close' blockade. First [[Rosyth Dockyard|Rosyth]] in Fife was considered, then [[Invergordon]] at [[Cromarty Firth]]. Delayed construction left these largely unfortified by the outbreak of the First World War. Scapa Flow had been used many times for British exercises in the years before the war and when the time came for the fleet to move to a northern station, it was chosen for the main base of the [[British Grand Fleet]]—unfortified.<ref name="castles">{{cite book| title=[[Castles of Steel]]| author=Robert K. Massie| author-link=Robert Massie| year=2004| publisher=Ballantine Books| isbn=0-345-40878-0}}{{Page needed|date=May 2011}}</ref>

[[John Jellicoe, 1st Earl Jellicoe|John Rushworth Jellicoe]], admiral of the Grand Fleet, was perpetually nervous about the possibility of submarine or destroyer attacks on Scapa Flow. Whilst the fleet spent almost the first year of the war patrolling the west coast of the British Isles, their base at Scapa was defensively reinforced, beginning with over sixty [[blockship]]s sunk in the many entrance channels between the southern islands to enable the use of submarine nets and [[Boom (navigational barrier)|booms]]. These blocked approaches were backed by minefields, artillery, and concrete barriers.<ref name="castles"/>

Two attempts to enter the harbour were made by [[Germany|German]] [[U-boat]]s during the war and neither was successful:
#{{SMU|U-18|Germany|2}} tried to enter in November 1914. A trawler searching for submarines rammed her, causing her to leak, prompting her flight and surfacing; one crew member died. 
#{{SMU|UB-116||2}} made a foray in October 1918 but encountered the sophisticated defences then in place. It was detected by [[hydrophone]]s before entering the anchorage, then destroyed by shore-triggered [[Naval mine|mines]], killing all 36 hands.<ref>{{cite Uboat.net|id=UB+116|name=UB 116|type=1sub}}</ref>

After the [[Battle of Jutland]], the German High Seas Fleet rarely ventured out of its bases at [[Wilhelmshaven]] and [[Kiel]] and in the last two years of the war the British fleet was considered to have such a commanding superiority of the seas that some components moved south to the first-class [[Rosyth Dockyard|dockyard at Rosyth]].