right|thumb|Scapa Flow viewed from its eastern end Scapa Flow (Old Norse: Skalpaflói - "bay of the long isthmus") is a body of water in the Orkney Islands, Scotland, United Kingdom, sheltered by the islands of Mainland, Graemsay, Burray, South Ronaldsay and Hoy. It is about . It has a shallow sandy bottom not deeper than and most of it about deep, and is one of the great natural harbours/anchorages of the world, with sufficient space to hold a number of navies. Viking ships anchored in Scapa Flow more than 1000 years ago, but it is best known as the site of the United Kingdom's chief naval base during World War I and World War II. The base was closed in 1956.

Viking era

The Viking expeditions to Orkney are recorded in detail in the 11th century Orkneyinga sagas and later texts such as the Hákonar saga Hákonarsonar. According to the latter, King Haakon IV of Norway anchored his fleet, including the flagship Kroussden that could carry nearly 300 men, at St Margaret's Hope on 5 August 1263 where he witnessed an eclipse of the sun prior to sailing south to the Battle of Largs. En route back to Norway Haakon anchored some of his fleet in Scapa Flow for the winter, but he died that December whilst staying at the Bishop's Palace in Kirkwall. In the 15th century towards the end of Norse rule in Orkney, the islands were run by the jarls from large manor farms some of which were sited at Burray, Burwick, Paplay, Hoy and Cairston (near Stromness) to guard the entrances to the Flow.

World War I

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Base for the British Grand Fleet

Historically, the main British naval bases were located near the English Channel to better face England's old enemies of France, Spain, and the Netherlands. In 1904, in response to the build-up of the German Kaiserliche Marine's High Seas Fleet, it was decided that a northern base was needed, to control the entrances to the North Sea. Originally, Rosyth was considered for the base, and then Invergordon at Cromarty Firth but construction in both places was delayed, leaving them largely unfortified by the time of the First World War. Scapa Flow was used many times for exercises in the years leading up to the War, and, when the time came for the fleet to move to a northern station, Scapa Flow was chosen for the main base of the British Grand Fleet, even though it was also unfortified.

John Rushworth Jellicoe, admiral of the Grand Fleet, was constantly nervous about potential submarine or destroyer attacks on Scapa Flow, and the base was reinforced with minefields, artillery, and concrete barriers starting in 1914. No German U-boats were able to enter the harbour during the war, and only two attempts were made. The first, by U-18, took place in November 1914; but the sub was rammed by a trawler searching for submarines while it was trying to enter Scapa Flow, causing the submarine to flee and then sink. The second attack, by UB-116, in October 1918, encountered the sophisticated defences then in place, was detected by hydrophones and then destroyed by shore-triggered mines before the boat could enter the anchorage.

After the Battle of Jutland the German High Seas Fleet rarely ventured out of its bases at Wilhelshaven 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 dockyard at Rosyth.

The scuttling of the German fleet

Following the German defeat in the First World War, 74 ships of the Kaiserliche Marine's High Seas Fleet were interned in Gutter Sound at Scapa Flow pending a decision on their future in the peace Treaty of Versailles. On 21 June 1919, after nine months of waiting, Rear Admiral Ludwig von Reuter, the German officer in command at Scapa Flow took the decision to scuttle the fleet because the negotiation period for the treaty had lapsed with no word of a settlement (he was not kept informed that there had been a last minute extension to finalise 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 British did eventually manage to beach the battleship Baden, the light cruisers Nurnberg, Frankfurt and Emden, together with 18 destroyers, but the remaining fifty-two ships, the vast bulk of the High Seas Fleet was sunk without loss of life, however, nine German sailors died when British forces opened fire as they attempted to scuttle their ship, reputedly the last casualties of the First World War.

The great salvage operation

Although many of the larger ships turned turtle and came to rest upside down or on their side in relatively deep water, (25m -45m) some - including the battlecruiser Moltke - were left with parts of their superstructure or upturned bows still protruding from the water or just below the surface. This posed a severe hazard to navigation, and small boats moving around the Flow regularly became snagged or beached on them. The British Admiralty initially declared that there would be no attempt at salvage and the sunken hulks would remain where they were. In the first few years after the war, there was abundant scrap metal as a result of the huge quantities of left over tanks, artillery and ordnance, but by the early twenties, the position had changed.

In 1922, the British Admiralty finally 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 The contract went to a wealthy scrap metal merchant Ernest Cox, who created a new company, Cox & Danks Ltd for the venture, and so began what is often called the greatest maritime salvage operation of all time.

During the next 8 years, Cox and his huge loyal workforce of divers, engineers and labourers applied all its ingenuity to the painstaking task of sealing the multiple holes in the wrecks and welding huge steel tubes to the hulls to allow compressed air to be pumped into the ships to raise them. First the relatively small destroyers were brought to the surface and sold for scrap to help finance the operation, then the bigger battleships and battlecruisers. Cox endured terrible 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 the General Strike of 1924, the salvage operation was about to grind to a halt due to a lack of coal to feed the boilers for the water pumps, until Cox ordered that the abundant fuel bunkers of the sunken battlecruiser Seydlitz 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. Eventually by 1939, Cox and the company he later sold out to, Metal Industries Ltd successfully raised 45 of the 52 scuttled ships. The last, the massive Derfflinger was raised from a record depth of 45 metres just before work was suspended with the start of WW2, before being towed to Rosyth where it was finally broken up in 1946

World War II

Primarily because of its great distance from German airfields, Scapa Flow was again selected as the main British naval base during World War II. However, the strong defences built up during WW1 had fallen into disrepair; defence against air attack was inadequate, the blockships sunk to stop U Boats penetrating had largely collapsed, and while there were anti-submarine nets in place over the three main entrances, they comprised only single-stranded looped wire. There was also a severe lack of the patrolling destroyers and other anti-U-Boat craft that had previously been available. Efforts belatedly began to repair the peacetime neglect.

On 14 October 1939, under the command of Günther Prien, U-47 penetrated Scapa Flow and sank the World War I–era battleship anchored in Scapa Bay. After firing its first torpedo, the submarine turned to make its escape, but upon realising that there was no immediate threat from surface vessels, returned to make another attack. The second torpedo blew a 30-foot (9 m) hole in the Royal Oak which, as a result, flooded and quickly capsized. Of the 1,400-man crew, 833 were lost. The wreck is now a protected war grave.

Three days after this submarine attack, four Luftwaffe Junkers Ju 88 bombers raided Scapa Flow in one of the first bombing attacks on Britain during the war. The attack badly damaged an old base ship, the battleship , with one bomber shot down by an anti-aircraft battery on Hoy.

New blockships were sunk, booms and mines were placed over the main entrances, increased anti-aircraft batteries were installed at crucial points and Winston 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. These "Churchill Barriers" now provide road access from the Mainland to Burray and South Ronaldsay, but block maritime traffic.

Today

Use by the petroleum industry

right|thumb|Petroleum tankers wait at anchor in Scapa Flow. The calm waters, relative to the North Sea provide a safe harbor for the oil terminal at Flotta Scapa Flow is one of the transfer and processing points for North Sea oil. A 30-inch, 128-mile long underwater pipeline brings oil from the Piper oilfield to the Flotta oil terminal. The Claymore and Tartan oil fields also feed into this line.

Scapa Flow Visitor Centre

The Scapa Flow visitor centre, at Lyness on the island of Hoy, is located in the former naval fuel pumping station and a converted storage tank. Exhibits include a large three dimensional representation of the island and of the ships as they were prior to scuttling. The island is accessible by local ferry several times daily from Houton. The centre has catering facilities for day trippers.

Scuba diving

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 recreational Scuba 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 twelve 'live aboard' 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 inside 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, current technology is now allowing 3D images of them to be seen.

The important wrecks comprise:

The battleships

The three sister battleships of the König Class; the SMS König, Kronprinz Wilhelm and the Markgraf which together formed the main component of the 3rd Battleship Squadron, and which took part in some of the fiercest fighting at Jutland, lie upside down with around 25m of water over them. Although they were never raised, they have been substantially salvaged over the years, having armour plate blasted away and non-ferrous metals removed. They remain however, extremely impressive dives, not least because of their sheer awesome size.

The light cruisers

Having much less bulky fighting tops, the four light cruisers SMS Dresden, SMS Karlsruhe, SMS Brummer and SMS Coln lie on their sides with around 16 - 20 metres of water over them. With the exception of the shallower Karlsruhe, they have been less heavily salvaged than the battleships and are much more accessible for divers.

Other dive locations

Additional sites of interest include the destroyer V 83, (which was raised and used by Cox as a working boat during his salvage operations, particularly on the Hindenburg, and later abandoned), the Churchill blockships, such as the Doyle in Burrah Sound, the U Boat UB 116 and the trawler James Barrie.

The forbidden wrecks

The wrecks of the and the dreadnought , which exploded at anchor during the First World War, are war graves protected under the Protection of Military Remains Act 1986. In addition, the wreck of the HMS Hampshire, which hit a mine while carrying Lord Kitchener North to Murmansk on 5th June 1916 and sank off the west coast of the mainland, is also a protected site. The 10,850 ton armoured cruiser, which went down in a heavy storm four days after the Battle of Jutland with only 12 surviving from its 655 crew, lies in 70 metres of water 1.5 miles off the steep desolate cliffs of Marwick Head, above which the Kitchener Memorial now stands as a silent memorial to those lost. Only divers of the British armed forces are permitted to visit them.

Gallery

See also

Lamb Holm

Glims Holm

Scapa (disambiguation)

Notes

References

A comprehensive guide to diving the wrecks and reefs of Scapa Flow. Describes the scuttling of the High Seas Fleet.

Thomson, William P. L. (2008) The New History of Orkney. Edinburgh. Birlinn. ISBN 9781841586960

External links

Scapa Flow Visitor Centre and Museum

Scapa Flow website by North Walls Community School

Scuttling of the High Seas Fleet at Scapa Flow

About the shipwrecks at Scapa Flow

Listing of German and scuttled ships.

Scapa Flow Marine Archaeology Project

Orkney Wireless Museum (in Kirwkwall)

Category:Underwater diving sites in the United Kingdom Category:Orkney Category:Ports and harbours of Scotland Category:Royal Navy bases in Scotland Category:Military of Scotland

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