Anti-submarine warfareAnti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are typically carried out to protect friendly shipping and coastal facilities from submarine attacks and to overcome blockades. Successful ASW operations typically involved a combination of sensor and weapon technologies, along with effective deployment strategies and sufficiently trained personnel.
World War IWorld War I or the First World War, often abbreviated as WWI or WW1, known contemporaneously as the Great War, was a major global conflict lasting from 1914 to 1918. It was fought between two coalitions, the Allies and the Central Powers. Fighting took place throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. The first decade of the 20th century saw increasing diplomatic tension between the European great powers.
Unrestricted submarine warfareUnrestricted submarine warfare is a type of naval warfare in which submarines sink merchant ships such as freighters and tankers without warning, as opposed to attacks per prize rules (also known as "cruiser rules") that call for warships to search merchantmen and place crews in "a place of safety" (for which lifeboats do not qualify, except under particular circumstances) before sinking them, unless the ship shows "persistent refusal to stop ... or active resistance to visit or search".
Armed merchantmanAn armed merchantman is a merchant ship equipped with guns, usually for defensive purposes, either by design or after the fact. In the days of sail, piracy and privateers, many merchantmen would be routinely armed, especially those engaging in long distance and high value trade. In more modern times, auxiliary cruisers were used offensively as merchant raiders to disrupt trade chiefly during both World War I and World War II, particularly by Germany.
False flagA false flag operation is an act committed with the intent of disguising the actual source of responsibility and pinning blame on another party. The term "false flag" originated in the 16th century as an expression meaning an intentional misrepresentation of someone's allegiance. The term was famously used to describe a ruse in naval warfare whereby a vessel flew the flag of a neutral or enemy country in order to hide its true identity. The tactic was originally used by pirates and privateers to deceive other ships into allowing them to move closer before attacking them.
Merchant raiderMerchant raiders are armed commerce raiding ships that disguise themselves as non-combatant merchant vessels. Germany used several merchant raiders early in World War I (1914–1918), and again early in World War II (1939–1945). The captain of a German merchant raider, Felix von Luckner, used the sailing ship SMS Seeadler for his voyage (1916–1917). The Germans used a sailing ship at this stage of the war because coal-fired ships had limited access to fuel outside of territories held by the Central Powers due to international regulations concerning refueling of combat ships in neutral countries.
MinesweeperA minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. The earliest known usage of the naval mine dates to the Ming dynasty. Dedicated minesweepers, however, only appeared many centuries later during the Crimean War, when they were deployed by the British. The Crimean War minesweepers were rowboats trailing grapnels to snag mines.
WarshipA warship or combatant ship is a naval ship that is built and primarily intended for naval warfare. Usually they belong to the armed forces of a state. As well as being armed, warships are designed to withstand damage and are typically faster and more maneuverable than merchant ships. Unlike a merchant ship, which carries cargo, a warship typically carries only weapons, ammunition and supplies for its crew. Warships usually belong to a navy, though they have also been operated by individuals, cooperatives and corporations.
Submarine warfareSubmarine warfare is one of the four divisions of underwater warfare, the others being anti-submarine warfare, mine warfare and mine countermeasures. Submarine warfare consists primarily of diesel and nuclear submarines using torpedoes, missiles or nuclear weapons, as well as advanced sensing equipment, to attack other submarines, ships, or land targets. Submarines may also be used for reconnaissance and landing of special forces as well as deterrence. In some navies they may be used for task force screening.
Second Happy TimeThe Second Happy Time (Zweite glückliche Zeit; officially Operation Paukenschlag ("Operation Drumbeat"), and also known among German submarine commanders as the "American Shooting Season") was a phase in the Battle of the Atlantic during which Axis submarines attacked merchant shipping and Allied naval vessels along the east coast of North America. The First Happy Time was in 1940–1941 in the North Atlantic and North Sea. Adolf Hitler and Benito Mussolini declared war on the United States on 11 December 1941, and as a result their navies could begin the Second Happy Time.