Scapa Flow

Scapa Flow is a large natural harbour in Orkney, Scotland, that served as the primary naval base for the British fleet during both World Wars. On 21 June 1919, German naval commander Ludwig von Reuter ordered the scuttling of the entire interned German fleet rather than allow it to be seized by the British. Although many of the sunken ships were subsequently salvaged, three battleships — Kronprinz Wilhelm, König, and Markgraf — along with four battle cruisers and numerous support vessels remain on the seabed, making Scapa Flow one of the most celebrated wreck-diving destinations in the world.

The harbour covers 324.5 square kilometres and holds just under one billion cubic metres of water. The bottom is sandy, with a maximum depth of 60 m (200 ft); most of the site sits at around 30 m (100 ft). Diving here is classified as hard/technical, reflecting both the depth of the major wrecks and the demands of wreck penetration.

A secondary focus of diving at Scapa Flow is the Churchill Barriers — a series of four causeways (numbered 1 through 4) created by deliberately sinking blockships to prevent enemy vessel access during the World Wars. These intentionally scuttled ships add further wreck-diving opportunities and are part of what gives the site its distinctive character. The wrecks throughout the harbour have developed rich marine habitats over the decades.