Battlecruiser in the context of "Battle of Jutland"

The dreadnought was the predominant type of battleship in the early 20th century. The first of the kind, the Royal Navy's HMS Dreadnought, had such an effect when launched in 1906 that similar battleships built after her were referred to as "dreadnoughts", and earlier battleships became known as pre-dreadnoughts. Her design had two revolutionary features: an "all-big-gun" armament scheme, with an unprecedented number of heavy-calibre guns, and steam turbine propulsion. As dreadnoughts became a crucial symbol of national power, the arrival of these new warships renewed the naval arms race between the United Kingdom and Germany. Dreadnought races sprang up around the world, including in South America, lasting up to the beginning of World War I. Successive designs increased rapidly in size and made use of improvements in armament, armour, and propulsion throughout the dreadnought era. Within five years, new battleships outclassed Dreadnought herself. These more powerful vessels were known as "super-dreadnoughts". Most of the original dreadnoughts were scrapped after the end of World War I under the terms of the Washington Naval Treaty, but many of the newer super-dreadnoughts continued serving throughout World War II.

Dreadnought-building consumed vast resources in the early 20th century, but there was only one battle between large dreadnought fleets. At the Battle of Jutland in 1916, the British and German navies clashed with no decisive result. The term dreadnought gradually dropped from use after World War I, especially after the Washington Naval Treaty, as virtually all remaining battleships shared dreadnought characteristics; it can also be used to describe battlecruisers, the other type of ship resulting from the dreadnought revolution.

The flight deck of an aircraft carrier is the surface on which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters and other VTOL aircraft is also referred to as the flight deck. The official U.S. Navy term for these vessels is "air-capable ships".

Flight decks have been in use upon ships since 1910, the American pilot Eugene Ely being the first individual to take off from a warship. Initially consisting of wooden ramps built over the forecastle of capital ships, a number of battlecruisers, including the British HMS Furious and Courageous class, the American USS Lexington and Saratoga, and the Japanese Akagi and battleship Kaga, were converted to aircraft carriers during the interwar period. The first aircraft carrier to feature a full-length flight deck, akin to the configuration of the modern vessels, was the converted liner HMS Argus which entered service in 1918. The armoured flight deck was another innovation pioneered by the Royal Navy during the 1930s. Early landing arrangements relied on the low speed and landing speed of the era's aircraft, being simply "caught" by a team of deck-hands in a fairly hazardous arrangement, but these became impractical as heavier aircraft with higher landing speeds emerged; thus an arrangement of arrestor cables and tailhooks soon became the favoured approach.

The Imperial Japanese Navy Air Service (大日本帝國海軍航空隊, Dai-Nippon Teikoku Kaigun Kōkū-tai) (IJNAS) was the air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.

The Japanese military acquired its first aircraft in 1910 and followed the development of air combat during World War I with great interest. Japan initially built European aircraft under license, but by the early 1930s Japanese factories were producing domestic designs. The Japanese also embarked on an ambitious aircraft carrier building program, launching the world's first purpose-built aircraft carrier, Hōshō, in 1922. Several excess battlecruisers and battleships were converted into aircraft carriers as well. As the organization assigned to the IJN's aircraft carriers, the Navy Air Service was tasked with the missions of national air defence, deep strike, naval warfare, and so forth. It retained this mission until its dissolution at the end of the Second World War.

The Deutschland class was a group of five pre-dreadnought battleships built for the German Kaiserliche Marine (Imperial Navy), the last vessels of that type to be built in Germany. The class comprised Deutschland, the lead ship, Hannover, Pommern, Schlesien, and Schleswig-Holstein. The ships closely resembled those of the preceding Braunschweig class, but with stronger armor and a rearranged secondary battery. Built between 1903 and 1908, they were completed after the launch of the revolutionary British all-big-gun battleship HMS Dreadnought in 1906. As a result, they were obsolescent before entering service. The ships nevertheless saw extensive service in the High Seas Fleet, Germany's primary naval formation, through the late 1900s and early 1910s, when they were used for training, which included overseas cruises.

Following the start of World War I in July 1914, the German fleet adopted a strategy of raids on the British coast, which the five Deutschland-class ships supported. These operations culminated in the Battle of Jutland on 31 May – 1 June 1916, where all five ships saw action, despite their marked inferiority to British dreadnoughts. Regardless, they intervened to protect the battered German battlecruisers from their British counterparts, allowing them to escape. In the confused night actions, Pommern was torpedoed and sunk by a British destroyer. After the battle, the four surviving ships were removed from front-line service and used for coastal defense through mid-1917. Thereafter, Hannover alone remained on patrol duty, while the rest were used as barracks or training ships. After Germany's defeat, the Treaty of Versailles permitted the postwar navy to retain several old battleships for coastal defense, including the four Deutschland-class ships.

The Iowa class was a class of six fast battleships ordered by the United States Navy in 1939 and 1940. They were initially intended to intercept fast capital ships such as the Japanese Kongō-class battlecruisers and serve as the "fast wing" of the U.S. battle line. The Iowa class was designed to meet the Second London Naval Treaty's "escalator clause" limit of 45,000-long-ton (45,700 t) standard displacement. Beginning in August 1942, four vessels, Iowa, New Jersey, Missouri, and Wisconsin, were completed; two more, Illinois and Kentucky, were laid down but canceled in 1945 and 1958, respectively, before completion, and both hulls were scrapped in 1958–1959.

The four Iowa-class ships were the last battleships commissioned in the U.S. Navy. All older U.S. battleships were decommissioned by 1947 and stricken from the Naval Vessel Register (NVR) by 1963. Between the mid-1940s and the early 1990s, the Iowa-class battleships fought in four major U.S. wars. In the Pacific Theater of World War II, they served primarily as fast escorts for Essex-class aircraft carriers of the Fast Carrier Task Force and also shelled Japanese positions. During the Korean War, the battleships provided naval gunfire support (NGFS) for United Nations forces, and in 1968, New Jersey shelled Viet Cong and Vietnam People's Army forces in the Vietnam War. All four were reactivated and modernized at the direction of the United States Congress in 1981, and armed with missiles during the 1980s, as part of the 600-ship Navy initiative. During Operation Desert Storm in 1991, Missouri and Wisconsin fired missiles and 16-inch (406 mm) guns at Iraqi targets.

The weather gage (sometimes spelled weather gauge or known as nautical gauge) is the advantageous position of a fighting sailing vessel relative to another. The concept is from the Age of Sail and is now antique. A ship at sea is said to possess the weather gage if it is in any position upwind of the other vessel -- having the wind at their back, speeding progress, when sailing towards the other ship. Proximity with the land, tidal and stream effects and wind variability due to geography (hills, cliffs, etc.) may also come into play.

• An upwind vessel is able to manoeuvre at will toward any downwind point, since the relative wind then moves aft.
• The fastest point of sail for a frigate typically have the wind blowing in the direction of travel, allowing that ship greater choice in the distance of separation. They could more easily disengage if damaged, and could more easily optimize for the range of their gunnery.
• However, in sailing warfare, the leeward ship gained a point of advantage in gunnery under heavier wind. When beating to windward, the vessel experiences heeling under the sideward pressure of the wind. This restricts gunnery, as cannon on the windward side are elevated, while the leeward gun ports aim into the sea or in heavy weather may be awash.
• Ships seeking to evade capture or attack have the advantage being downwind if they are faster vessels or are close to friendly land -- but in heavier weather a strong disadvantage if there is danger of grounding on a lee shore
• A vessel downwind of another, in attempting to attack upwind, is constrained to trim sail as the relative wind moves forward and cannot point too far into the wind for fear of being headed. The helm is typically more responsive on a downwind course. Sailing upwind involves frequent changes of sail: more tiring for the crew, more chance for mishap, and more taxing for the helm.
• A ship with the weather gage, turning downwind to attack, may alter course at will to bring starboard and port guns to appropriate elevations.

The term has had a literary rebirth in the popular seafaring novels of C.S. Forester, Patrick O'Brian and Alexander Kent. One of the last times that weather gage was perhaps a factor in a surface naval engagement was in the Battle of the Denmark Strait in 1941, where the German battleship Bismarck and the heavy cruiser Prinz Eugen held the weather gage over the British battleship HMS Prince of Wales and the battlecruiser HMS Hood. Being upwind, the German ships had the advantage that their rangefinders were drier than the British rangefinders facing the spray. The weather restricted the visual range to much less than the gun range.

HMS Agamemnon was one of two Lord Nelson-class pre-dreadnought battleships launched in 1906 and completed in 1908. She was the Royal Navy's second-to-last pre-dreadnought battleship to be built, followed by her sister ship, Lord Nelson. She was assigned to the Channel Fleet when the First World War began in 1914. The ship was transferred to the Mediterranean Sea with Lord Nelson in early 1915 to participate in the Dardanelles Campaign. She made a number of bombardments against Turkish fortifications and in support of British troops. Agamemnon remained in the Mediterranean after the conclusion of that campaign to prevent the German battlecruiser SMS Goeben and light cruiser Breslau from breaking out into the Mediterranean. Agamemnon shot down the German Zeppelin LZ-55 (LZ-85) during a bombing mission over Salonica in 1916. On 30 October 1918, the Ottoman Empire signed the Armistice of Mudros on board the ship while she was anchored at Lemnos in the northern Aegean Sea. She was converted to a radio-controlled target ship following her return to the United Kingdom in March 1919 and began service in 1921. Agamemnon was the last pre-dreadnought in service with the Royal Navy; she was replaced by Centurion at the end of 1926 and sold for scrap in January 1927.

The Russian battleship Potemkin (Russian: Князь Потёмкин Таврический, romanized: Kniaz Potyomkin Tavricheskiy, "Prince Potemkin of Taurida") was a pre-dreadnought battleship built for the Imperial Russian Navy's Black Sea Fleet. She became famous during the Revolution of 1905, when her crew mutinied against their officers. This event later formed the basis for Sergei Eisenstein's 1925 silent film Battleship Potemkin.

After the mutineers sought asylum in Constanța, Romania, and after the Russians recovered the ship, her name was changed to Panteleimon. She accidentally sank a Russian submarine in 1909 and was badly damaged when she ran aground in 1911. During World War I, Panteleimon participated in the Battle of Cape Sarych in late 1914. She covered several bombardments of the Bosphorus fortifications in early 1915, including one where the ship was attacked by the Ottoman battlecruiser Yavuz Sultan Selim – Panteleimon and the other Russian pre-dreadnoughts present drove her off before she could inflict any serious damage. The ship was relegated to secondary roles after Russia's first dreadnought battleship entered service in late 1915. She was by then obsolete and was reduced to reserve in 1918 in Sevastopol.

Bismarck was the first of two Bismarck-class battleships built for Nazi Germany's Kriegsmarine. Named after Chancellor Otto von Bismarck, the ship was laid down at the Blohm & Voss shipyard in Hamburg in July 1936 and launched in February 1939. Work was completed in August 1940, when she was commissioned into the German fleet. Bismarck and her sister ship Tirpitz were the largest battleships ever built by Germany, and two of the largest built by any European power.

In the course of the warship's eight-month career, Bismarck conducted only one offensive operation that lasted eight days in May 1941, codenamed Rheinübung. The ship, along with the heavy cruiser Prinz Eugen, was to break into the Atlantic Ocean and raid Allied shipping from North America to Great Britain. The two ships were detected several times off Scandinavia, and British naval units were deployed to block their route. At the Battle of the Denmark Strait, the battlecruiser HMS Hood initially engaged Prinz Eugen, probably by mistake, while HMS Prince of Wales engaged Bismarck. In the ensuing battle Hood was destroyed by the combined fire of Bismarck and Prinz Eugen, which then damaged Prince of Wales and forced her retreat. Bismarck suffered sufficient damage from three hits by Prince of Wales to force an end to the raiding mission.