HMCS Cowichan (J146)

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.

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.

North Van Ship Repair, later known as Pacific Dry Dock was a shipyard in the city of North Vancouver, British Columbia, Canada which built many of the Bangor-class minesweeper, Fort ships and Victory ships for Britain and Canada during World War II. Located just west of Lonsdale Avenue adjoining the Burrard Dry Dock, it was eventually absorbed into Burrard. The site was pulled down in the early 1980s and became the Lonsdale Quay and the Insurance Corporation of British Columbia (ICBC) building.

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.

British Columbia, commonly abbreviated as BC, is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, forests, lakes, mountains, inland deserts and grassy plains, and borders the province of Alberta to the east, the territories of Yukon and Northwest Territories to the north, and the US states of Washington, Idaho and Montana to the south and Alaska to the northwest. With an estimated population of 5.3 million as of 2022, it is Canada's third-most populous province. The capital of British Columbia is Victoria and its largest city is Vancouver. Vancouver is the third-largest metropolitan area in Canada; the 2021 census recorded 2.6 million people in Metro Vancouver.

Bermuda is a British Overseas Territory in the North Atlantic Ocean. The Bermuda archipelago consists of 181 islands with a total land area of 54 km2 (21 sq mi). The closest land outside the territory is in the US state of North Carolina, approximately 1,035 km (643 mi) to the northwest.

The Newfoundland Escort Force (NEF) was a Second World War naval command created on 20 May 1941 as part of the Allied convoy system in the Battle of the Atlantic. Created in response to the movement of German U-boats into the western Atlantic Ocean, the Newfoundland Escort Force (NEF) was instituted to cover the convoy escort gap that existed between the local convoy escort in Canada and the United Kingdom. The Royal Canadian Navy provided the majority of naval vessels to the NEF along with its commander Commodore Leonard W. Murray, with units from the British, Norwegian, Polish, French and Dutch navies also assigned. The NEF was reconstituted as part of the Mid-Ocean Escort Force in 1942.

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.

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 Free French Naval Forces were the naval arm of the Free French Forces during the Second World War. They were commanded by Admiral Émile Muselier.

Aconit was one of the nine Flower-class corvettes lent by the Royal Navy to the Free French Naval Forces. During World War II, she escorted 116 convoys, spending 728 days at sea. She was awarded the Croix de la Libération and the Croix de Guerre 1939–1945, and was cited by the British Admiralty. Following the war she was used as whaling ship for three different companies from 1947 to 1964.

Alysse was one of the nine Flower-class corvettes lent by the Royal Navy to the Free French Naval Forces.