
Theodor Arps was a German naval officer, most recently Deputy Admiral in World War II, from 1940 to 1945 Judge at the Reichskriegsgericht. Theodor Arps was notable for managing the German Naval Intelligence Service (German:Marinenachrichtendienst) from 1 October 1934 to 31 December 1939. Arps' time at the Marinenachrichtendienst was known for increased rearmament at the agency, a modernizing period, preparing and undertaking assurance testing on the Naval Enigma for secure message use cases, training and mobilization planning and an increasingly efficient and modern signal intelligence architecture that was the culmination of two decades of work during the interwar period.

The battle between the Australian light cruiser HMAS Sydney and the German auxiliary cruiser Kormoran was a single-ship action that occurred on 19 November 1941, off the coast of Western Australia. Sydney, with Captain Joseph Burnett commanding, and Kormoran, under Fregattenkapitän Theodor Detmers, encountered each other approximately 106 nautical miles off Dirk Hartog Island. Both ships were destroyed in the half-hour engagement.

Admiral of the Fleet Andrew Browne Cunningham, 1st Viscount Cunningham of Hyndhope, was a senior officer of the Royal Navy during the Second World War. He was widely known by his initials, "ABC".

Karl Dönitz was a German admiral during the Nazi era who briefly succeeded Adolf Hitler as the German head of state in 1945. As Supreme Commander of the Navy since 1943, he played a major role in the naval history of World War II. He was convicted of war crimes at the Nuremberg trials in 1946.

The Imperial Japanese Navy was the navy of the Empire of Japan from 1868 until 1945, when it was dissolved following Japan's surrender in World War II. The Japan Maritime Self-Defense Force (JMSDF) was formed circa 1952-1954 after the dissolution of the IJN.

The Imperial Japanese Navy Air Service 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.

Captain Norman "Bill" Limbury Auchinleck Jewell MBE DSC was an officer in the Royal Navy.

The Kriegsmarine was the navy of Nazi Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war Reichsmarine (1919–1935) of the Weimar Republic. The Kriegsmarine was one of three official branches, along with the Heer and the Luftwaffe of the Wehrmacht, the German armed forces from 1933 to 1945.

Erhard Maertens or Eberhard Maertens was a German Vizeadmiral of the Kriegsmarine during World War II. From 16 June 1941 to 5 May 1943, he was Chief of Office of Naval Intelligence, Naval War Command in the Oberkommando der Marine. Maertens was known for underestimating British intelligence, and specifically, overrating the security of the Naval Enigma cipher machine. In 1941, he held a naval enquiry into the strength of Naval Enigma security after the capture of U-boat U-570, and attributed all the suspicious losses in U-boats at the time to the British Huff-Duff. In the second enquiry, ordered by the Commander-in-Chief of the Navy Karl Dönitz, in May 1943, he investigated a number of areas, in which exculpated Enigma security in the end, for the second time, incorrectly blaming British 9.7 centimetre centimetric radar for the massive losses in U-boats by mid 1943.

The Marina Nazionale Repubblicana was the navy of the Italian Social Republic, a German puppet state in Italy.

The Battle of the Mediterranean was the name given to the naval campaign fought in the Mediterranean Sea during World War II, from 10 June 1940 to 2 May 1945.

The Attack on Mers-el-Kébir on 3 July 1940, during the Second World War, was a British naval attack on French Navy ships at the naval base at Mers El Kébir, at Oran, on the coast of French Algeria. The attack was part of Operation Catapult, a British plan to neutralise or destroy French ships to prevent them falling into German hands in the aftermath of the Allied defeat in the Battle of France. The British bombardment of the base killed 1,297 French servicemen, sank a battleship and damaged five other ships, for a British loss of five aircraft shot down and two crewmen killed.

The organization of the Kriegsmarine refers to the operational and administrative structure of the German Navy from 1935 to 1945. Many of the organizational tenets of the Kriegsmarine were inherited from its predecessor the Reichsmarine. As World War II unfolded, the Kriegsmarine expanded to cover additional regions and responsibilities, most significant of which was the occupation of France and the Battle of the Atlantic.

Admiral of the Fleet Sir Alfred Dudley Pickman Rogers Pound, was a British senior officer of the Royal Navy. He served in the First World War as a battleship commander, taking part in the Battle of Jutland with notable success, contributing to the sinking of the German cruiser Wiesbaden. He served as First Sea Lord, the professional head of the Royal Navy, for the first four years of the Second World War. In that role his greatest achievement was his successful campaign against the German U-boats and the winning of the Battle of the Atlantic but his judgment has been questioned over the failed Norwegian Campaign in 1940, his dismissal of Admiral Dudley North in 1940, and Japan's sinking of Prince of Wales and Repulse in late 1941. His order in July 1942 to disperse Convoy PQ 17 and withdraw its covering forces, to counter a threat from heavy German surface ships, led to its destruction by submarines and aircraft. His health failed in 1943 and he resigned, dying shortly thereafter.

Erich Johann Albert Raeder was a German admiral who played a major role in the naval history of World War II. Raeder attained the highest possible naval rank, that of Grand Admiral, in 1939, becoming the first person to hold that rank since Henning von Holtzendorff. Raeder led the Kriegsmarine for the first half of the war; he resigned in January 1943 and was replaced by Karl Dönitz. At the Nuremberg Trials he was sentenced to life imprisonment but was released early owing to failing health.

Lieutenant Commander Richard Prendergast Raikes was an officer in the Royal Navy notable for being the commanding officer of the submarine HMS Tuna that launched the canoes during Operation Frankton in 1942. His part in the operation was the basis for the character "Reeves" in the 1955 war film The Cockleshell Heroes, played by Christopher Lee.

The Regia Marina was the navy of the Kingdom of Italy from 1861 to 1946. In 1946, with the birth of the Italian Republic, the Regia Marina changed its name to Marina Militare.

The Women's Royal Naval Service was the women's branch of the United Kingdom's Royal Navy. First formed in 1917 for the First World War, it was disbanded in 1919, then revived in 1939 at the beginning of the Second World War, remaining active until integrated into the Royal Navy in 1993. WRNS included cooks, clerks, wireless telegraphists, radar plotters, weapons analysts, range assessors, electricians and air mechanics.