HMS Cossack (F03)

A flotilla, or naval flotilla, is a formation of small warships that may be part of a larger fleet.

The I-class destroyers were a group of nine destroyers, including a flotilla leader, built for the Royal Navy during the 1930s. Four similar ships were ordered by the Turkish Navy, of which two were purchased for the Royal Navy, bringing the number of these ships British service to 11—although three of the original ships had been lost by the time Inconstant and Ithuriel were commissioned. The I-class served in World War II and six were lost, with a seventh ship being written off.

The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used.

Length overall is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth.

The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water.

The draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water.

The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h. The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non-SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.

Fuel oil is any of various fractions obtained from the distillation of petroleum. Such oils include distillates and residues. Fuel oils include heavy fuel oil, marine fuel oil (MFO), bunker fuel, furnace oil (FO), gas oil (gasoil), heating oils, diesel fuel and others.

In a navy, a rate, rating or bluejacket is a junior enlisted sailor who is not a warrant officer or commissioned officer. Depending on the country and navy that uses it, the exact term and the range of ranks that it refers to may vary.

Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself.

Sterling is the currency of the United Kingdom and nine of its associated territories. The pound is the main unit of sterling, and the word "pound" is also used to refer to the British currency generally, often qualified in international contexts as the British pound or the pound sterling.

The Firth of Forth is the estuary, or firth, of several Scottish rivers including the River Forth. It meets the North Sea with Fife on the north coast and Lothian on the south.

Scapa Flow is a body of water in the Orkney Islands, Scotland, sheltered by the islands of Mainland, Graemsay, Burray, South Ronaldsay and Hoy. Its sheltered waters have played an important role in travel, trade and conflict throughout the centuries. Vikings anchored their longships in Scapa Flow more than a thousand years ago. It was the United Kingdom's chief naval base during the First and Second World Wars, but the facility was closed in 1956.

Seafield is a coastal strip situated on the Firth of Forth between Leith and Portobello in north-east Edinburgh, Scotland. The area is mainly commercial, and has little housing.

Leith is a port area in the north of the city of Edinburgh, Scotland, founded at the mouth of the Water of Leith.

Admiral Graf Spee was a Deutschland-class "Panzerschiff", nicknamed a "pocket battleship" by the British, which served with the Kriegsmarine of Nazi Germany during World War II. The vessel was named after World War I Admiral Maximilian von Spee, commander of the East Asia Squadron who fought the battles of Coronel and the Falkland Islands, where he was killed in action. She was laid down at the Reichsmarinewerft shipyard in Wilhelmshaven in October 1932 and completed by January 1936. The ship was nominally under the 10,000 long tons (10,000 t) limitation on warship size imposed by the Treaty of Versailles, though with a full load displacement of 16,020 long tons (16,280 t), she significantly exceeded it. Armed with six 28 cm (11 in) guns in two triple gun turrets, Admiral Graf Spee and her sisters were designed to outgun any cruiser fast enough to catch them. Their top speed of 28 knots left only the few battlecruisers in the Anglo-French navies fast enough and powerful enough to sink them.

Altmark was a German oil tanker and supply vessel, one of five of a class built between 1937 and 1939. She is best known for her support of the German commerce raider, the "pocket battleship" Admiral Graf Spee and her subsequent involvement in the "Altmark Incident". In 1940 she was renamed the Uckermark and used as supply tanker for the battleships Scharnhorst and Gneisenau during Operation Berlin before sailing to Japan on September 1942 as a blockade breaker.

Admiral of the Fleet Sir Philip Louis Vian, & Two Bars was a Royal Navy officer who served in both World Wars.

Jøssingfjorden is a fjord in Sokndal municipality in Rogaland county, Norway. The 3-kilometre (1.9 mi) long fjord is narrow and deep and is surrounded by mountains. It sits about 4 kilometres (2.5 mi) southeast of the municipal centre of Hauge. There is some settlement on the southeastern side of the fjord: the villages of Li, Vinterstø, and Bu. There is a road that runs along the southeast coast of the fjord, with sharp hairpin turns leading down from the mountains to the shore of the fjord both heading north and south from the fjord.

Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of Norway. Bouvet Island, located in the Subantarctic, is a dependency of Norway; it also lays claims to the Antarctic territories of Peter I Island and Queen Maud Land. The capital and largest city in Norway is Oslo.

Gibraltar is a British Overseas Territory and city located at the southern tip of the Iberian Peninsula. It has an area of 6.7 km2 (2.6 sq mi) and is bordered to the north by Spain. The landscape is dominated by the Rock of Gibraltar, at the foot of which is a densely populated town area, home to over 32,000 people, primarily Gibraltarians.

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is 242,495 square kilometres (93,628 sq mi), with an estimated 2023 population of over 68 million people.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.

Klaus Bargsten was the captain and sole survivor of the sunken U-521. He was a recipient of the Knight's Cross of the Iron Cross.

The ship's cat has been a common feature on many trading, exploration, and naval ships dating to ancient times. Cats have been carried on ships for many reasons, most importantly to control rodents. Vermin aboard a ship can cause damage to ropes, woodwork, and more recently, electrical wiring. In addition, rodents threaten ships' stores, devour crews' foodstuff, and can cause economic damage to ships' cargo, such as grain. They are also a source of disease, which is dangerous for ships that are at sea for long periods of time. Rat fleas are carriers of plague, and rats on ships were believed to be a primary vector of the Black Death.

Unsinkable Sam is the nickname of a ship's cat who purportedly served during World War II with both the Kriegsmarine and the Royal Navy and survived the sinking of three ships.

HMS Ark Royal was an aircraft carrier of the Royal Navy that was operated during the Second World War.