HMS Guysborough

The Halcyon class was a class of 21 oil-fired minesweepers built for the British Royal Navy between 1933 and 1939. They were given traditional small ship names used historically by the Royal Navy and served during World War II.

The Fundy-class minesweepers were a class of four minesweepers operated by the Royal Canadian Navy during the Second World War. All four ships entered service in 1938 and the class were discarded in 1945, sold for mercantile service. Three ended up sold to Chinese interests, while one remained active in Canada until 1987.

The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is called a compression-ignition engine. This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine or a gas engine.

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.

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.

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 QF 12-pounder 12-cwt gun (Quick-Firing) was a common, versatile 3-inch (76.2 mm) calibre naval gun introduced in 1894 and used until the middle of the 20th century. It was produced by Armstrong Whitworth, Elswick and used on Royal Navy warships, exported to allied countries, and used for land service. In British service "12-pounder" was the rounded value of the projectile weight, and "12 cwt (hundredweight)" was the weight of the barrel and breech, to differentiate it from other "12-pounder" guns.

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.

The keel is the bottom-most longitudinal structural element on a vessel. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. The laying of the keel is often the initial step in the construction of a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ships construction.

The City of North Vancouver is a city on the north shore of Burrard Inlet, British Columbia, Canada. It is the smallest in area and the most urbanized of the North Shore municipalities. Although it has significant industry of its own – including shipping, chemical production, and film production – the city is considered to be a suburb of Vancouver. The city is served by the Royal Canadian Mounted Police, British Columbia Ambulance Service, and the North Vancouver City Fire Department.

Baltimore is the most populous city in the U.S. state of Maryland, the fourth most populous city in the Mid-Atlantic, and the 30th most populous city in the United States with a population of 585,708 in 2020. Baltimore was designated an independent city by the Constitution of Maryland in 1851, and today it is the most populous independent city in the nation. As of 2021, the population of the Baltimore metropolitan area was estimated to be 2,838,327, making it the nation's 20th largest metropolitan area. Baltimore is located about 40 miles (64 km) north northeast of Washington, D.C., making it a principal city in the Washington–Baltimore combined statistical area (CSA), the third-largest CSA in the nation, with a 2021 estimated population of 9,946,526.

A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, any vessel or a particular vessel type, akin to anti-infantry vs. anti-vehicle mines. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour; or defensively, to protect friendly vessels and create "safe" zones. Mines allow the minelaying force commander to concentrate warships or defensive assets in mine-free areas giving the adversary three choices: undertake an expensive and time-consuming minesweeping effort, accept the casualties of challenging the minefield, or use the unmined waters where the greatest concentration of enemy firepower will be encountered.

Lunenburg is a port town on the South Shore of Nova Scotia, Canada. Founded in 1753, the town was one of the first British attempts to settle Protestants in Nova Scotia.

Horta is a municipality and city in the Portuguese archipelago of the Azores encompassing the island of Faial. The population in 2011 was 15,038 in an area of 173.06 square kilometres (66.82 sq mi) The city of Horta itself has a population of about 7,000.

Plymouth is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately 36 miles (58 km) south-west of Exeter and 193 miles (311 km) south-west of London. It is bordered by Cornwall to the west and south-west.

A coup de grâce is a death blow to end the suffering of a severely wounded person or animal. It may be a mercy killing of mortally wounded civilians or soldiers, friends or enemies, with or without the sufferer's consent.

HMS Loring (K565) was a British Captain-class frigate of the Royal Navy in commission during World War II. Originally constructed as the United States Navy Evarts-class destroyer escort DE-520, she served in the Royal Navy from 1943 to 1945.