Scapa Flow hosts an oil port, theFlotta oil terminal. In good weather, itsroadstead (water of moderate conditions) allows ship-to-ship transfers ofcrude oil products. The world's first ship-to-ship transfer ofliquefied natural gas (LNG) took place in Scapa Flow in 2007 transferring 132,000 m³ of LNG. This occurred in 2007, under the direction of Excelerate Energy, between the vesselsExcalibur andExcelsior.
Scapa Flow has a shallow sandy bottom not deeper than 60 metres (200 ft), and chiefly of approximately 30 m (100 ft) deep; it is one of the great natural harbours and anchorages of the world, with sufficient space to shelter multiple navies. The harbour has an area of 324.5 square kilometres (125.3 sq mi).[3]
The Viking expeditions to Orkney are recorded in detail in the 11th centuryOrkneyinga sagas, as well as in later texts such as theHákonar saga Hákonarsonar. According to the latter, KingHaakon IV of Norway anchored his fleet, including theflagshipKroussden that could carry nearly 300 men, on 5 August 1263 atSt Margaret's Hope, where he saw aneclipse of the sun before he sailed south to theBattle of Largs. En route back to Norway, Haakon anchored some of his fleet in Scapa Flow for the winter, but he died that December while staying at theBishop's Palace inKirkwall.[5] In the 15th century towards the end of Norse rule in Orkney, the islands were run by thejarls from large manor farms, some of which were atBurray,Burwick, Paplay,Hoy, andCairston (nearStromness) to guard the entrances to the Flow.[6]
Historically, the main British naval bases were near theEnglish Channel to counter the continental naval powers: theDutch Republic, France, and Spain.
In 1904, in response to the build-up of theImperial German Navy'sHigh Seas Fleet, Britain decided that a northern base was needed to control the entrances to theNorth Sea, as part of a revised policy of distant rather than closeblockade. FirstRosyth inFife was considered, thenInvergordon atCromarty 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 theBritish Grand Fleet—unfortified.[7]
John Rushworth Jellicoe, admiral of the Grand Fleet, was perpetually nervous about the possibility ofsubmarine ordestroyer attacks on Scapa Flow. Whilst the fleet spent most of the first year of the war patrolling the west coast of the British Isles, their base at Scapa was defensively reinforced, beginning with over sixtyblockships sunk in the many entrance channels between the southern islands to enable the use of submarine nets andbooms. These blocked approaches were backed by minefields, artillery, and concrete barriers.[7]
Two attempts to enter the harbour were made by GermanU-boats during the war and neither was successful:
U-18 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.
UB-116 made a foray in October 1918 but encountered the sophisticated defences then in place. It was detected byhydrophones before entering the anchorage, then destroyed by shore-triggeredmines, killing all 36 hands.[8]
After theBattle of Jutland, theGerman fleet rarely ventured out of its bases atWilhelmshaven andKiel, 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 thedockyard at Rosyth.
Following the German defeat, 74 ships of their High Seas Fleet were interned inGutter Sound at Scapa Flow pending a decision on their future in the peaceTreaty of Versailles.
On 21 June 1919, after seven months of waiting, German Rear AdmiralLudwig von Reuter made the decision toscuttle the fleet because the negotiation period for the treaty had lapsed with no word of a settlement. He was not informed that there had been a last-minute extension to finalize the details.
After waiting for the bulk of the British fleet to leave on exercises, he gave the order to scuttle the ships to prevent their falling into British hands. The Royal Navy made desperate efforts to board the ships to prevent the sinkings, but the German crews had spent the idle months preparing for the order, welding bulkhead doors open, laying charges in vulnerable parts of the ships, and quietly dropping important keys and tools overboard so valves could not be shut.
The Royal Navy managed to beach the battleshipBaden, thelight cruisersEmden,Nürnberg, andFrankfurt and 18 destroyers whereas 53 ships, the vast bulk of the High Seas Fleet, were sunk. Nine German sailors died on some of these ships when British forces opened fire as they attempted to scuttle the ships, reputedly the last casualties of the war.
Although many of the larger ships "turned turtle" and came to rest upside down or on their sides in relatively deep water (25–45 m), some—including the battlecruiserMoltke—were left with parts of their superstructure or upturned bows still protruding from the water, while others had settled just below the surface.
These ships posed a severe hazard to navigation; small boats, trawlers, and drifters regularly became snagged on them with the rise and fall of the tides. The Admiralty initially declared that there would be no attempt at salvage, and that the sunken hulks would remain where they were, to "rest and rust". In the years immediately following the war, the country enjoyed an abundance of scrap metal as a result of the huge quantities of leftover tanks, artillery and ordnance. By the early 1920s, however, the situation had changed.
In 1922, the Admiralty invited tenders from interested parties for the salvage of the sunken ships, although at the time few believed that it would be possible to raise the deeper wrecks.[2] The contract went to a wealthy engineer and scrap metal merchant,Ernest Cox, who created a new company, a division of Cox & Danks Ltd, for the venture, and so began what is often called the greatest maritime salvage operation of all time.[2]
During the next eight years, Cox and his workforce of divers, engineers, and labourers engaged in the complex task of raising the sunken fleet. First the relatively small destroyers were winched to the surface using pontoons and floating docks to be sold for scrap to help finance the operation, then the bigger battleships and battlecruisers were lifted, by sealing the multiple holes in the wrecks, and welding to the hulls long steel tubes which protruded above the water, for use as airlocks. In this fashion the submerged hulls were made into air-tight chambers and raised with compressed air, still inverted, back to the surface.
Cox endured bad luck and frequent fierce storms which often ruined his work, swamping and re-sinking ships which had just been raised. At one stage, during theGeneral Strike of 1926, the salvage operation was about to grind to a halt due to a lack of coal to feed the many boilers for the water pumps and generators. Cox ordered that the abundant fuel bunkers of the sunken (but only partly submerged) battlecruiserSeydlitz be broken into to extract the coal with mechanical grabs, allowing work to continue.
Although he ultimately lost money on the contract, Cox kept going, employing new technology and methods as conditions dictated. By 1939, Cox and Metal Industries Ltd. (the company that he had sold out to in 1932) had successfully raised 45 of the 52 scuttled ships. The last, the massiveDerfflinger, was raised from a record depth of 45 metres just before work was suspended with the start of the Second World War, before being towed to Rosyth where it was broken up in 1946.
Scapa Flow in April 1942KingGeorge VI visiting theHome Fleet based at Scapa Flow, March 1943Blockship, Scapa Flow
Primarily because of its great distance from German airfields, Scapa Flow was again selected as the main British naval base during the Second World War.[10]
The strong defences built during the First World War had fallen into disrepair. Defence against air attack was inadequate andblockships sunk to stop U-boats from penetrating had largely collapsed. While there were anti-submarine nets in place over the three main entrances, they were made only of single-stranded looped wire; there was also a severe lack of the patrolling destroyers and other anti-submarine craft that had previously been available. Efforts began belatedly to repair peacetime neglect, but were not completed in time to prevent a successful penetration by enemy forces.[11]
On 14 October 1939, under the command ofGünther Prien,U-47 penetrated Scapa Flow and sank the First World War-era battleshipHMS Royal Oak anchored in Scapa Bay.[12] After firing its first torpedo salvo, the submarine turned to make its escape; but, upon realising that there was no immediate threat from surface vessels, it returned for another attack. The second torpedo salvo blew a 30-foot (9.1 m) hole in theRoyal Oak, which flooded and quickly capsized. Of the 1,400-man crew, 833 were lost. The wreck is now a protectedwar grave.[13][14]John Gunther in December 1939 called the attack "the single most extraordinary feat of the war so far".[15]
Three days after the submarine attack, fourLuftwaffeJunkers Ju 88 bombers ofKampfgeschwader 1/30 led by group commander Hauptmann Fritz Doench raided Scapa Flow on 17 October in one of the first bombing attacks on Britain during the war. The attack badly damaged an old base ship, the decommissioned battleshipHMS Iron Duke, which was then beached at Ore Bay by a tug. One man died and 25 were injured. One of the bombers was shot down by the No. 1 gun of the 226 Heavy Anti-Aircraft Battery on Hoy. Three of the crew died, while the radio operator Fritz Ambrosius was badly burned but managed to parachute down.[16]
New blockships were sunk, booms and mines were placed over the main entrances, coast defence and anti-aircraft batteries were installed at crucial points, andWinston Churchill ordered the construction of a series of causeways to block the eastern approaches to Scapa Flow; they were built by Italian prisoners of war held in Orkney, who also built theItalian Chapel. These "Churchill Barriers" now provide road access from Mainland to Burray and South Ronaldsay, but block maritime traffic. An airfield,RAF Grimsetter (which later became HMSRobin), was built and commissioned in 1940.[17]
The Scapa Flow Visitor Centre is atLyness on Hoy (fromHáey meaning 'high island') the second largest of Orkney. Morning to evening ferries run fromHouton on the Mainland.
The Visitor Centre occupies a converted naval fuel pumping station and storage tank and next to it is a round stone-built battery emplacement and artillery gun as well as other decommissioned arsenal. It features a large model of the island, Scapa Flow and of the German warships.
The wreckage of the remaining seven ships of the German fleet (and some other sites such as the blockships) has become increasingly popular as a venue for recreationalscuba divers, and is regularly listed in dive magazines and internet forums among the top dive sites in the UK, Europe, and even the world. Although other locations, for example the Pacific regions, offer warmer water and better visibility, there are very few other sites which can offer such an abundance of large, historic wrecks lying in close proximity and shallow, relatively benign diving conditions. As of 2010, at least twelveliveaboard boats—mostly converted trawlers with bunk rooms in their former holds—take recreational divers out to the main sites, primarily from the main harbour at Stromness. Diving provides a substantial amount of trade and income for the local economy.
Divers must first obtain a permit from the Island Harbour Authorities, which is available through diving shops and centres. The wrecks are mostly located at depths of 35 to 50 metres. Divers are permitted to enter the wrecks, but not to retrieve artefacts located within 100 metres of any wreck. However, time and tide has washed broken pieces of ships' pottery and glass bottles into shallow waters and onto beaches. The underwater visibility, which can vary between 2 and 20 metres, is not sufficient to view all the length of most wrecks at once; however, technology has allowed3D images of them to be seen.[19][20]
The three sister battleships of theKönig class (SMS König,SMS Kronprinz andSMS Markgraf) formed the main component of the 3rd Battleship Squadron which took part in fierce fighting at theBattle of Jutland far off the coast ofJutland, Denmark (31 May to 1 June 1916), and their upturned hulls are around 25 m deep. Never raised, they have been salvaged incrementally: armour plate was blasted away and non-ferrous metals were removed. Some of this material may have been obtained forspecialized uses because it was not subject to the radiation put into the atmosphere bynuclear weapons, which were exploded in the open air from 1945 to 1963. Thus it was not made more radioactive bynuclear fallout.[21] They also form highly-rated dive sites chiefly due to their depth.[citation needed]
The light cruisersSMS Dresden,SMS Karlsruhe,SMS Brummer andSMS Cöln have modestfighting tops, lie side-on with around 16–20 metres of water above, are more accessible for divers and save for the shallowest,Karlsruhe, and are less salvaged (stripped of valuable materials) than the battleships.
Additional sites of interest include the destroyerSMS V83, which was raised and used by Cox as a working boat during his salvage operations, particularly onSMS Hindenburg, then later abandoned; the Churchill blockships, such as theTabarka, theGobernador Bories, and theDoyle in Burra Sound; the U-boatSM UB-116; and the trawlerJames Barrie. Also, some large items from many of the ship hulls thatwere raised (such as the main gun turrets, which fell away from the ships as they capsized) were never salvaged, and still rest on the seabed in close proximity to the impact craters gouged by the scuttled ships.
The wrecks of the battleshipsRoyal Oak andVanguard (the latter of which exploded at anchor during the First World War) are war graves designated as Controlled Sites under theProtection of Military Remains Act 1986—only divers of the British armed forces may visit these wrecks.[22]
George, S. C. (1981).Jutland to Junkyard.Edinburgh: Paul Harris Publishing.ISBN0-86228-029-X. Describes the scuttling of the High Seas Fleet.
Thomson, William P. L. (2008).The New History of Orkney. Edinburgh: Birlinn.ISBN978-1-84158-696-0.
Wood, Lawson (2007).Scapa Flow Dive Guide. AquaPress Publishing.ISBN978-1-905492-04-6. A comprehensive guide to diving the wrecks and reefs of Scapa Flow.