Anti-submarine warfare in the context of "Halifax-class frigate"

The Royal Navy (RN) is the naval warfare force of the United Kingdom, responsible for defending the UK, the Crown Dependencies, and the Overseas Territories from naval attack or invasion. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the English Navy of the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service.

From the early 18th century until the Second World War, it was the world's most powerful navy. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superiority. Following World War I, it was significantly reduced in size. During the Cold War, the Royal Navy transformed into a primarily anti-submarine force, hunting for Soviet submarines and mostly active in the GIUK gap. Following the collapse of the Soviet Union, its focus returned to expeditionary operations.

Naval aviation is the application of military air power by navies, either from warships that can embark aircraft (e.g. aircraft carriers, amphibious assault ships and aircraft cruisers) or from coastal naval air stations.It often involves navalised aircraft, specifically designed for naval use.Seaborne aviation encompasses similar activities not restricted to navies, including marines and coast guards, such as in U.S. naval aviators. As with most army aviation units, naval aviation units are generally separate from a nation's dedicated air force.

Naval aviation operations are typically projected by way of carrier-based aircraft, which must be sturdy enough to withstand the demands of shipborne operations at sea. They must be able to take off from a short runway (typically the flight deck of an aircraft carrier) and be sturdy and flexible enough to come to a sudden stop when landing; they typically have robust folding or swinging wings that reduce the occupied space and thus allow more of them to be stored in below-decks hangars and limited parking spaces on flight decks. These aircraft are designed for many tactical purposes, including aerial combat, airstrike/close air support, anti-submarine warfare, early warning, search and rescue, matériel transport, weather observation, patrol and reconnaissance, and wide-area command and control duties.

A military helicopter is a helicopter that is either specifically designed for or converted for usage by a military. A military helicopter's mission is a function of its design or conversion. The most common use of military helicopters is airlift, but transport helicopters can be modified or converted to perform other missions such as combat search and rescue (CSAR), medical evacuation (MEDEVAC), serving as an airborne command post, or even armed with weapons for close air support. Specialized military helicopters are intended to conduct specific missions. Examples of specialized military helicopters are attack helicopters, observation helicopters and anti-submarine warfare (ASW) helicopters.

Submarine navigation underwater requires special skills and technologies not needed by surface ships. The challenges of underwater navigation have become more important as submarines spend more time underwater, travelling greater distances and at higher speed. Military submarines travel underwater in an environment of total darkness with neither windows nor lights. Operating in stealth mode, they cannot use their active sonar systems to ping ahead for underwater hazards such as undersea mountains, drilling rigs or other submarines. Surfacing to obtain navigational fixes is precluded by pervasive anti-submarine warfare detection systems such as radar and satellite surveillance. Antenna masts and antenna-equipped periscopes can be raised to obtain navigational signals but in areas of heavy surveillance, only for a few seconds or minutes; current radar technology can detect even a slender periscope while submarine shadows may be plainly visible from the air.

A carrier-based aircraft (also known as carrier-capable aircraft, carrier-borne aircraft, carrier aircraft or aeronaval aircraft) is a navalised aircraft designed for seaborne flight operations from aircraft carriers. The term is generally applied only to shipborne fixed-wing aircraft that require a runway of some sort for takeoff and landing, as VTOL aircraft such as helicopters are inherently capable of adapting to flight operations from a wide variety of ships (not just aircraft carriers) as long as the served vessel is equipped with helipads or a sufficiently spacious deck that can provide a reliable landing area, which include helicopter carriers, amphibious assault ships, aviation-capable surface combatants (cruisers, destroyers, frigates and some corvettes), container ships and even cruiseliners.

Carrier-based aircraft are designed for many purposes including aerial combat, surface attack, anti-submarine warfare (ASW), search and rescue (SAR), carrier onboard delivery (COD), weather observation, reconnaissance and airborne early warning and control (AEW&C). Such aircraft must be able to take off from the short distance available on the carrier's flight deck and be sturdy enough to withstand the abrupt forces exerted by on a pitching deck due to sea waves. Some modern carrier aircraft are designed for catapult-assisted takeoffs and thus also need to be constructed more robust airframes and landing gears that can handle sudden forward accelerations. Arrestor hook is mandatory feature for those designed for CATOBAR or STOBAR landing, while thrust vectoring or tiltrotor nacelles are commonly seen in those capable of V/STOL operations. In addition, their wings are generally larger (thus can generate more lift) than the land-launched counterparts, and are typically able to fold up or swing back for taxiing, pushback and parking in tight quarters.

An anti-ship missile (AShM or ASM) is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming variety, and many use a combination of inertial guidance and active radar homing. A large number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship; it is also possible for anti-ship missiles to be guided by radio command all the way.

Many anti-ship missiles can be launched from a variety of weapons systems including surface warships (also referred to as ship-to-ship missiles), submarines, bombers, fighter planes, patrol planes, helicopters, shore batteries, land vehicles, and, conceivably, even infantrymen firing shoulder-launched missiles. The term surface-to-surface missile (SSM) is used when appropriate. The longer-range anti-ship missiles are often called anti-ship cruise missiles. Several countries are also developing anti-ship ballistic missiles.

Aircraft ordnance or ordnance (in the context of military aviation) is any expendable weaponry (e.g. bombs, missiles, rockets and gun ammunition) used by military aircraft. The term is often used when describing the payload of air-to-ground weaponry that can be carried by the aircraft or the weight that has been dropped in combat. Aircraft ordnance also includes air-to-air, anti-ship and anti-submarine weapons.

Some aircraft types can carry a wide variety of ordnance – for example, the Fairchild AU-23 Peacemaker could use forward-firing gun pods, 500 and 250 pound bombs, napalm units, cluster bomb units, flares, rockets, smoke grenades and propaganda leaflet dispensers.

The Royal Navy (RN) is the naval warfare force of the United Kingdom, responsible for defending the UK, the Crown Dependencies, and the Overseas Territories from naval attack or invasion. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the English Navy of the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service.

From the early 18th century until the Second World War, it was the world's most powerful navy. The Royal Navy played a key part in establishing and defending the British Empire, and four Imperial fortress colonies and a string of imperial bases and coaling stations secured the Royal Navy's ability to assert naval superiority. Following World War I, it was significantly reduced in size. During the Cold War, the Royal Navy transformed into a primarily anti-submarine force, hunting for Soviet submarines and mostly active in the GIUK gap. Following the collapse of the Soviet Union, its focus returned to expeditionary operations. Following a projected £2 billion overspend acknowledged by the MOD in 2025, the Royal Navy announced it will reduce overseas training in the Indo-Pacific and the Middle East.