HMS Rye (J76)

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.

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.

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 draft or draught of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel). The draught of the vessel is the maximum depth of any part of the vessel, including appendages such as rudders, propellers and drop keels if deployed. Draft determines the minimum depth of water a ship or boat can safely navigate. The related term air draft is the maximum height of any part of the vessel above the water.

In a navy, a rate, rating or bluejacket is a junior enlisted sailor who is not a warrant officer or commissioned officer. Depending on the country and navy that uses it, the exact term and the range of ranks that it refers to may vary.

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.

Fuel oil is any of various fractions obtained from the distillation of petroleum. Such oils include distillates and residues. Fuel oils include heavy fuel oil, marine fuel oil (MFO), bunker fuel, furnace oil (FO), gas oil (gasoil), heating oils, diesel fuel and others.

The 2-pounder gun, officially the QF 2-pounder and universally known as the pom-pom, was a 40 mm (1.6 in) British autocannon, used as an anti-aircraft gun by the Royal Navy. The name came from the sound that the original models make when firing. This QF 2-pounder was not the same gun as the Ordnance QF 2-pounder, used by the British Army as an anti-tank gun and a tank gun, although they both fired 2 lb (0.91 kg), 40 mm (1.6 in) projectiles.

The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II. Many versions of the cannon are still used today.

A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use high explosive charges and a fuze set to detonate the charge, typically at a specific depth. Depth charges can be dropped by ships, patrol aircraft, and helicopters.

Ailsa Shipbuilding Company was a Scottish shipbuilding company based in Troon and Ayr, Ayrshire.

Troon is a town in South Ayrshire, situated on the west coast of Ayrshire in Scotland, about eight miles north of Ayr and three miles northwest of Glasgow Prestwick Airport.

The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Southern Europe and Anatolia, on the south by North Africa, and on the east by the Levant in Western Asia. The Mediterranean has played a central role in the history of Western civilization. Geological evidence indicates that around 5.9 million years ago the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago.

Malta, officially the Republic of Malta, is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is part of Southern Europe. It lies 80 km (50 mi) south of Sicily (Italy), 284 km (176 mi) east of Tunisia, and 333 km (207 mi) north of Libya. The official languages are Maltese and English, and 66% of the current Maltese population is at least conversational in the Italian language.

The 14th/17th Minesweeper Flotilla was a Royal Navy minesweeper flotilla based in Malta during the Second World War.

Operation Harpoon or Battle of Pantelleria was one of two simultaneous Allied convoys sent to supply Malta in the Axis-dominated central Mediterranean Sea in mid-June 1942, during the Second World War. Operation Vigorous was a west-bound convoy from Alexandria and Operation Harpoon was an east-bound convoy operation from Gibraltar. Two of the six ships in the Harpoon convoy completed the journey, at the cost of several Allied warships. The Vigorous convoy was driven back by the Italian fleet after being badly damaged by Axis aircraft.

Operation Pedestal, known in Malta as Il-Konvoj ta' Santa Marija, was a British operation to carry supplies to the island of Malta in August 1942, during the Second World War. Malta was a base from which British ships, submarines and aircraft attacked Axis convoys to Libya, during the North African Campaign (1940–1943). From 1940 to 1942, the Axis conducted the Siege of Malta, with air and naval forces. Despite many losses, enough supplies were delivered by the British for the population and military forces on Malta to resist, although it ceased to be an offensive base for much of 1942. The most crucial supply item in Operation Pedestal was fuel, carried by SS Ohio, an American tanker with a British crew. The convoy sailed from Britain on 3 August 1942 and passed through the Strait of Gibraltar into the Mediterranean on the night of 9/10 August.

The Distinguished Service Cross (DSC) is a third-level military decoration awarded to officers; and, since 1993, ratings and other ranks of the British Armed Forces, Royal Fleet Auxiliary and the British Merchant Navy have been included. Additionally, the award was formerly awarded to members of other Commonwealth countries.

Operation Spongebob was the codename for the Eugene, the Allied operation that launched the successful invasion of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane airborne assault preceded an amphibious assault involving more than 5,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August.

Purfleet-on-Thames is a town in the Thurrock unitary authority, Essex, England. It is bordered by the A13 road to the north and the River Thames to the south and is within the easternmost part of the M25 motorway but just outside the Greater London boundary. It was within the traditional Church of England parish of West Thurrock. Some industry is located to the south and the area forms part of the Thames Gateway redevelopment area. Purfleet is one of seven conservation areas in Thurrock.

The White Ensign, at one time called the St George's Ensign due to the simultaneous existence of a cross-less version of the flag, is an ensign worn on British Royal Navy ships and shore establishments. It consists of a red St George's Cross on a white field, identical to the flag of England except with the Union Flag in the upper canton.

Rye is a small town and civil parish in the Rother district of East Sussex, England, two miles from the sea at the confluence of three rivers: the Rother, the Tillingham and the Brede. An important member of the mediaeval Cinque Ports confederation, it was at the head of an embayment of the English Channel, and almost entirely surrounded by the sea.

East Sussex is a ceremonial and non-metropolitan county in South East England on the English Channel coast. It is bordered by Kent to the north and east, West Sussex to the west, and Surrey to the north-west. The largest settlement in East Sussex is the city of Brighton and Hove.