Editing Scapa Flow (section)

==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 diving|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 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 computer graphics|3D]] images of them to be seen.<ref>{{Cite web|url=http://www.scapaflowwrecks.com|title=Scapa Flow : Historic Wreck Site|website=scapaflowwrecks.com|access-date=2017-08-10|archive-date=17 October 2021|archive-url=https://web.archive.org/web/20211017182159/http://www.scapaflowwrecks.com/|url-status=live}}</ref><ref>{{cite web|url=http://www.divernet.com/Wrecks/159269/scapa_flow_in_3d.html|title=Scapa Flow in 3D|publisher=DiverNet|archive-url=https://web.archive.org/web/20110606082802/http://www.divernet.com/Wrecks/159269/scapa_flow_in_3d.html|archive-date=2011-06-06|access-date=2009-10-16}}</ref>

The important wrecks are:

===German battleships===

The three sister battleships of the {{sclass|König|battleship|4}}: {{SMS|König}}, {{SMS|Kronprinz|1914|6}} and {{SMS|Markgraf}} formed the main component of the 3rd Battleship Squadron which took part in fierce fighting at the [[Battle of Jutland]] far off the coast of Jutland, Denmark (31 May to 1 June 1916) and their upturned hulls are around 25&nbsp;m deep. Never raised, they have been salvaged incrementally: armour plate blasted away and non-ferrous metals removed. Some of this material may have been obtained for specialized uses because it was not subject to the radiation put into the atmosphere by [[nuclear weapon]]s, which were exploded in the open air from 1945 to 1963.  Thus it was not made more radioactive by [[nuclear fallout]].<ref>[https://www.straightdope.com/21344067/is-steel-from-scuttled-german-warships-valuable-because-it-isn-t-contaminated-with-radioactivity Is steel from scuttled German warships valuable because it isn’t contaminated with radioactivity?]</ref> They also form highly rated dive sites chiefly due to their depth.{{citation needed|date=September 2017}}

===German light cruisers===

The [[light cruiser]]s {{SMS|Dresden|1917|6}}, {{SMS|Karlsruhe|1916|6}}, {{SMS|Brummer}} and {{SMS|Cöln|1916|6}} have modest fighting tops, lie side-on with around 16–20 metres of water above, are more accessible for divers and save for the shallowest, ''Karlsruhe'', are less salvaged (stripped of valuable materials) than the battleships.

===Other vessels===

Additional sites of interest include the destroyer {{SMS|V83||6}}, which was raised and used by Cox as a working boat during his salvage operations, particularly on {{SMS|Hindenburg}}, then later abandoned; the Churchill blockships, such as the ''Tabarka'', the ''Gobernador Bories'', and the ''Doyle'' in Burra Sound; the U-boat {{SMU|UB-116}}; and the trawler ''James Barrie''. Also, some large items from many of the ship hulls that ''were'' 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.

===War grave wrecks===

The wrecks of the battleships {{HMS|Royal Oak|08|2}} and {{HMS|Vanguard|1909|2}} (the latter of which exploded at anchor during the First World War) are [[war grave]]s designated as Controlled Sites under the [[Protection of Military Remains Act 1986]]—only divers of the British armed forces may visit these wrecks.<ref>{{citation | title = Wrecks designated as Military Remains | publisher = Maritime and Coastguard Agency | url = http://www.mcga.gov.uk/c4mca/mcga-environmental/mcga-dops_row_receiver_of_wreck/mcga-dops-row-protected-wrecks/mcga-dops-sar-row.htm | access-date = 2006-12-27 | archive-date = 16 May 2010 | archive-url = https://web.archive.org/web/20100516031259/http://www.mcga.gov.uk/c4mca/mcga-environmental/mcga-dops_row_receiver_of_wreck/mcga-dops-row-protected-wrecks/mcga-dops-sar-row.htm | url-status = live }}</ref>