Destroyer in the context of "Depth charge"

HMS Greyhound was a G-class destroyer built for the Royal Navy in the 1930s. Greyhound participated in the Norwegian Campaign in April 1940, the Dunkirk evacuation in May and the Battle of Dakar in September before being transferred to the Mediterranean Fleet in November. The ship generally escorted the larger ships of the Mediterranean Fleet as they protected convoys against attacks from the Italian Fleet. She sank two Italian submarines while escorting convoys herself in early 1941. Greyhound was sunk by German Junkers Ju 87 Stuka dive bombers north-west of Crete on 22 May 1941 as she escorted the battleships of the Mediterranean Fleet attempting to intercept the German sea-borne invasion forces destined for Crete.

A naval ship (or naval vessel) is a military ship (or sometimes boat, depending on classification) that is used by a navy. Naval ships are differentiated from civilian ships by construction and purpose. Generally, naval ships are damage resilient and armed with weapon systems, though armament on troop transports is light or non-existent.

Naval ships designed primarily for naval warfare are termed warships, as opposed to support (auxiliary ships) or shipyard operations.

The Georges Leygues class (Type C70 AS or Type F70 AS) consisted of seven guided-missile destroyers built for the French Navy during the Cold War. They were multi-role ships due to their Exocet and Crotale missile armament, making them especially suitable for the defence of strategic positions, show of force operations, or as high seas escorts. The design was initially officially known as a "corvette" with the designation C70, but were internationally labelled an "anti-submarine destroyer" (hence the "D" in the hull numbers). Subsequently, the French referred to the ships as "frigates" with the designation F70.

A squadron, or naval squadron, is a significant group of warships which is nonetheless considered too small to be designated a fleet. A squadron is typically a part of a fleet. Between different navies there are no clear defining parameters to distinguish a squadron from a fleet (or from a flotilla), and the size and strength of a naval squadron varies greatly according to the country and time period. Groups of small warships, or small groups of major warships, might instead be designated flotillas by some navies according to their terminology. Since the size of a naval squadron varies greatly, the rank associated with command of a squadron also varies greatly.

Before 1864 the entire fleet of the Royal Navy was divided into three squadrons, the red, the white, and the blue. Each Royal Navy squadron alone was more powerful than most national navies. Today, a squadron might number three to ten vessels, which might be major warships, transport ships, submarines, or small craft in a larger task force or a fleet. A squadron may be composed of one type of ship of various types tasked with a specific mission such as coastal defense, blockade, or minesweeping. In the United States Navy, the term squadron has always been used for formations of destroyers and submarines.

A carrier battle group (CVBG) is a naval fleet consisting of an aircraft carrier capital ship and its large number of escorts, together defining the group. The CV in CVBG is the United States Navy hull classification code for an aircraft carrier.

The first naval task forces built around carriers appeared just prior to and during World War II. The Imperial Japanese Navy (IJN) was the first to assemble many carriers into a single task force, known as the Kido Butai. This task force was used with devastating effect in the Japanese attack on Pearl Harbor. The Kido Butai operated as the IJN's main carrier battle group until four of its carriers were sunk at the Battle of Midway. In contrast, the United States Navy deployed its large carriers in separate formations, with each carrier assigned its own cruiser and destroyer escorts. These single-carrier formations would often be paired or grouped together for certain assignments, most notably the Battle of the Coral Sea and Midway. By 1943, however, large numbers of fleet and light carriers became available, which required larger formations of three or four carriers. These groups eventually formed the Fast Carrier Task Force, which became the primary battle unit of the U.S. Third and Fifth Fleets.

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.

Mahan-class destroyers of the United States Navy were a series of 18 destroyers of which the first 16 were laid down in 1934. The last two of the 18, Dunlap and Fanning (this pair laid down in 1935), are sometimes considered a separate ship class. All 18 were commissioned in 1936 and 1937. Mahan was the lead ship, named for Rear Admiral Alfred Thayer Mahan, an influential historian and theorist on sea power.

The Mahans featured improvements over previous destroyers, with 12 torpedo tubes, superimposed gun shelters, and generators for emergency use. The standard displacement increased from 1,365 tons to 1,500 tons. The class introduced a new steam propulsion system that combined increases in pressure and temperature with a new type of lightweight steam turbine, which proved simpler and more efficient than the Mahans' predecessors—to such an extent that it was used on many subsequent wartime US destroyers.

USS Johnston (DD-557) was a Fletcher-class destroyer built for the United States Navy during World War II. She was named after Lieutenant John V. Johnston, an officer of the US Navy during the American Civil War. Johnston was laid down in May 1942 and was launched on 25 March 1943. She entered active duty on 27 October 1943 under the command of Lieutenant Commander Ernest E. Evans and was assigned to the US Pacific Fleet. Johnston provided naval gunfire support for American ground forces during the Gilbert and Marshall Islands campaign in January and February 1944 and again, after three months of patrol and escort duty in the Solomon Islands, during the recapture of Guam in July. Thereafter, Johnston was tasked with escorting escort carriers during the Mariana and Palau Islands campaign and the liberation of the Philippines.

On 25 October 1944, while assigned as part of the escort to six escort carriers, Johnston, two other Fletcher-class destroyers, and four destroyer escorts were engaged by a large Imperial Japanese Navy flotilla. In what became known as the Battle off Samar, Johnston and the other escort ships charged the Japanese ships to protect nearby US carriers and transport craft. After engaging several Japanese capital ships and a destroyer squadron, Johnston was sunk with 187 dead, including Evans. Johnston's wreck was discovered on 30 October 2019 but was not properly identified until March 2021. Lying more than 20,000 feet (6,100 m) below the surface of the ocean, it was the deepest shipwreck ever surveyed until the 22 June 2022 discovery of USS Samuel B. Roberts, sunk during the same engagement.

The Puerto Rico campaign was the American military sea and land operation in Puerto Rico during the Spanish–American War, which resulted in the invasion, occupation, and annexation of the archipelago and island by the United States, and the cession of said territory by Spain. The offensive began on May 12, 1898, when the United States Navy attacked the capital, San Juan. Though the damage inflicted on the city was minimal, the Americans were able to establish a blockade in the city's harbor, San Juan Bay. On June 22, the cruiser Isabel II and the destroyer Terror delivered a Spanish counterattack, but were unable to break the blockade and Terror was damaged.

The land offensive began on July 25, when 1,300 infantry soldiers led by Major General Nelson A. Miles disembarked off the coast of Guánica. After winning the first skirmish, the Americans advanced to Coamo, where they engaged Puerto Rican and Spanish troops in battle. With two defenders and four Americans dead, the defenders retreated. The United States forces were able to seize control of Fajardo on August 1, but were forced to withdraw on August 5 after a group of 200 Puerto Rican–Spanish soldiers led by Pedro del Pino counterattacked, while most civilian inhabitants fled to the nearby lighthouse. The Americans encountered more opposition as they advanced towards the main island's interior. They engaged in two crossfires in Guamaní River and Coamo, both of which were inconclusive as the allied soldiers retreated. A battle in San Germán concluded in a similar fashion with the Spanish retreating to Lares.

A carrier strike group (CSG) is a type of carrier battle group of the United States Navy. It is an operational formation composed of roughly 7,500 personnel, usually an aircraft carrier, at least one cruiser, a destroyer squadron of at least two destroyers or frigates, and a carrier air wing of 65 to 70 aircraft. A carrier strike group also, on occasion, includes submarines, attached logistics ships and a supply ship. The carrier strike group commander operationally reports to the commander of the numbered fleet, who is operationally responsible for the area of waters in which the carrier strike group is operating.

Strike groups comprise a principal element of U.S. power projection capability; a single supercarrier holds enough firepower to rival the air forces of entire nations. Previously referred to as carrier battle groups (a term still used by other nations), they are often referred to by the carrier they are associated with (e.g., Enterprise Strike Group). As of March 2023 there are 11 carrier strike groups in the U.S. Navy.