Orkney Islands is located in the north of Scotland, the geographical coordinates are 59 degrees north latitude, 3 degrees west longitude, its southern end is only 16 kilometers away from the Scottish coast, composed of more than 70 islands, and divided into two island groups in the north and south, of which more than 20 are inhabited, with a total area of 990 square kilometers, the largest island is the main island, with an area of 523 square kilometers, the capital is Kirkwall, and Orkney belongs to the temperate maritime climate. Summers are fairly cool and winters are colder. It is also known for being windy, especially in winter. Despite its remote location, the Orkney Islands have a long history of settling here as early as the Stone Age 8,500 years ago, and today it still preserves the oldest and best-preserved Neolithic sites in Europe. Norman rule over Orkney lasted for nearly six centuries, in 1468 King Chris Thyonne I of Norway married his daughter Princess Margaret to King James III of Scotland as his wife, because he could not get the dowry, he could only mortgage the Orkney Islands to Scotland, but he eventually had no money to pay the dowry, so in February 1472 the Orkney Islands were officially ceded to Scotland, and eventually became the inherent territory of the British Empire.
Scarpa Bay is a wide harbor surrounded by many islands in the south of the Orkney Islands, its north is barriered by the main island of Orkney, and the south side is surrounded by a slightly smaller island, of which the larger area is Hoy Island, Gram Walled Island, Flota Island, South Ronald Cold Island and Barre Island, Kapa Bay covers an area of about 312 square kilometers, the seabed is an undulating and gentle sand bottom, the maximum water depth is not more than 60 meters, the average depth is about 30 meters, it is one of the best natural harbors in the world, and its space is enough to accommodate a huge fleet.
This remote bay in the northern part of the Kingdom of Britain is the main combat base of the British Royal Navy, once stationed in the world's first powerful fleet, including dozens of battleships have been used as anchorages, is an important cornerstone for the defense of Britain's sea frontier, providing an important guarantee for the Royal Navy to seize sea supremacy. There were many major events that shook the history of the war: during the First World War, in May 1916, it was from this that the British Naval Grand Fleet set out to the city of Jutland to engage the German High Seas Fleet, where most of the capital ships of the German High Seas Fleet sank en masse; During World War II, the British Navy's home fleet also set sail, going deep into the ocean to pursue german warships such as "Bismarck" and "Scharnhorst", and the German Navy's U-47 submarine night attack anchorage and sink the "Royal Oak" is one of the most famous examples of surprise attacks in history.
As a vital naval base, Chikapa Bay was one of the most highly fortified military targets, and the British Navy spared no effort to build and set up a large number of defensive facilities throughout the Orkney Islands to prevent enemy attacks on anchorages from the sea, underwater and air, and to ensure the safe berthing of the fleet. In response to the shelling and amphibious landings of the enemy fleet, coastal platforms were built on the island and coastal defense forces were deployed; In order to prevent surface ships and submarines from bursting into the harbor, water cabinets, anti-submarine nets, blocking boats and other obstacles in the water have been arranged in each access channel; In order to defend against the enemy's air threat, anti-aircraft guns, blocking balloons, searchlights and radars were used to form air defense barriers, and a number of airfields were built, and a considerable number of military aircraft were stationed to provide air cover, which together formed a very tight land, sea and air defense system during World War II.
However, the establishment of the defensive attachment to Scarpa Bay took a considerable time, and when it was not yet perfected, the cunning enemy would always try to find its weakness and launch an attack, and achieved a remarkable success, thus prompting the British to strengthen the defense more comprehensively and eliminate the loopholes. In fact, apart from the surprise attack of the U-47, Scarpa Bay was extremely safe for most of the time as the fleet anchorage, allowing the fleet to sit back and rest without worry.