German torpedo boat TA37

The Spica class were a class of torpedo boats of the Regia Marina during World War II. These ships were built as a result of a clause in the Washington Naval Treaty, which stated that ships with a tonnage of less than 600 could be built in unlimited numbers. Thirty-two ships were built between 1934 and 1937, thirty of which entered service with Italy and two which were sold to the Swedish Navy in 1940. The two units in Swedish service were classed as destroyers until 1953, then re-classified as corvettes. Although commonly referred to as torpedo boats due to their smaller displacement, the Spica class armaments were similar in design to destroyers, and were intended for anti-submarine duties, although they often had to fight aircraft and surface forces as well. Twenty-three vessels were lost during World War II.

A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several roles.

In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy, or battle group and defend them against powerful short-range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish Navy as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War.

Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship.

Length overall is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth.

Length between perpendiculars is the length of a ship along the summer load line from the forward surface of the stem, or main bow perpendicular member, to the after surface of the sternpost, or main stern perpendicular member. When there is no sternpost, the centerline axis of the rudder stock is used as the aft end of the length between perpendiculars.

The beam of a ship is its width at its widest point. The maximum beam (BMAX) is the distance between planes passing through the outer extremities of the ship, beam of the hull (BH) only includes permanently fixed parts of the hull, and beam at waterline (BWL) is the maximum width where the hull intersects the surface of the water.

The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used.

A steam turbine is a machine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884. Fabrication of a modern steam turbine involves advanced metalwork to form high-grade steel alloys into precision parts using technologies that first became available in the 20th century; continued advances in durability and efficiency of steam turbines remains central to the energy economics of the 21st century.

The knot is a unit of speed equal to one nautical mile per hour, exactly 1.852 km/h. The ISO standard symbol for the knot is kn. The same symbol is preferred by the Institute of Electrical and Electronics Engineers (IEEE), while kt is also common, especially in aviation, where it is the form recommended by the International Civil Aviation Organization (ICAO). The knot is a non-SI unit. The knot is used in meteorology, and in maritime and air navigation. A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour.

A dual-purpose gun is a naval artillery mounting designed to engage both surface and air targets.

The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto to the northwest and the Po Valley. The countries with coasts on the Adriatic are Albania, Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia.

The Aegean Sea is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some 215,000 square kilometres. In the north, the Aegean is connected to the Marmara Sea, which in turn connects to the Black Sea, by the straits of the Dardanelles and the Bosphorus, respectively. The Aegean Islands are located within the sea and some bound it on its southern periphery, including Crete and Rhodes. The sea reaches a maximum depth of 2,639m to the west of Karpathos. The Thracian Sea and the Sea of Crete are main subdivisions of the Aegean Sea.

A corvette is a small warship. It is traditionally the smallest class of vessel considered to be a proper warship. The warship class above the corvette is that of the frigate, while the class below was historically that of the sloop-of-war.

The Battle of Ist was a naval engagement in Adriatic Sea, between the islands of Škarda and Molat, off the island of Ist, on 29 February 1944. The engagement was fought between two Free French Naval Forces destroyers and a Kriegsmarine force of two corvettes, two torpedo boats and three minesweepers. The German flotilla had been deployed to escort a freighter. In the ensuing engagement the French managed to destroy the German freighter and a corvette in return for no loss before withdrawing.

Le Malin was one of six Le Fantasque-class large destroyers built for the Marine Nationale during the 1930s. The ship entered service in 1935 and participated in the Second World War. When war was declared in September 1939, all of the Le Fantasques were assigned to the Force de Raid, tasked with hunting down German commerce raiders and blockade runners. Le Malin and two of her sister ships were based in Dakar, French West Africa, to patrol the Central Atlantic for several months in late 1939. They returned to Metropolitan France before the end of the year and were transferred to French Algeria in late April 1940 in case Italy decided to enter the war. Le Malin played a minor role in the Norwegian Campaign in late April. After returning to the Mediterranean, she screened French cruisers several times as they unsuccessfully hunted for Italian ships after Italy declared war in June.

Le Terrible was one of six Le Fantasque-class large destroyers built for the Marine Nationale during the 1930s. The ship entered service in 1936 and participated in the Second World War. When war was declared in September 1939, all of the Le Fantasques were assigned to the Force de Raid which was tasked to hunt down German commerce raiders and blockade runners. Le Terrible and two of her sister ships were based in Dakar, French West Africa, to patrol the Central Atlantic for several months in late 1939. They returned to Metropolitan France before the end of the year and were transferred to French Algeria in late April 1940 in case Italy decided to enter the war. She screened French cruisers once as they unsuccessfully hunted for Italian ships after Italy declared war in June.

HMS Belvoir was a Hunt-class destroyer of the Royal Navy. She was a member of the third subgroup of the class, and saw service in the Second World War. She was adopted by the civil community of Sutton in Ashfield, Nottinghamshire during Warship Week in 1942.

HMS Whaddon (L45) was a Type I Hunt-class destroyer of the Royal Navy built by Alexander Stephen & Sons of Linthouse, Govan and launched on 16 July 1940. She was laid down on 27 July 1939 and commissioned 28 February 1941. She was adopted by the civil community of Newport Pagnell in Buckinghamshire, as part of the Warship Week campaign in 1942.

The Gulf of Patras is a branch of the Ionian Sea in Western Greece. On the east, it is closed by the Strait of Rion between capes Rio and Antirrio, near the Rio-Antirrio bridge, that is the entrance of the Gulf of Corinth. On the west, it is bounded by a line from Oxeia island to Cape Araxos. To the north it is bounded by the shore of Aetolia-Acarnania in continental Greece, and to the south by Achaea in the Peloponnese peninsula. It is 40–50 km (25–31 mi) long, 10–20 km (6.2–12.4 mi) wide, and has an area of 350–400 km2.

The Corinth Canal is an artificial canal in Greece, that connects the Gulf of Corinth in the Ionian Sea with the Saronic Gulf in the Aegean Sea. It cuts through the narrow Isthmus of Corinth and separates the Peloponnese from the Greek mainland, arguably making the peninsula an island. The canal was dug through the Isthmus at sea level and has no locks. It is 6.4 kilometres in length and only 24.6 metres wide at sea level, making it impassable for many modern ships. It is currently of little economic importance and is mainly a tourist attraction.

HMS Termagant was a T-class destroyer of the Royal Navy that saw service during the Second World War. She was built by William Denny and Brothers, of Dumbarton and launched on 22 March 1943. She was scrapped in 1965.

HMS Tuscan was a T-class destroyer of the British Royal Navy that served during the Second World War and was scrapped in 1966.