Royal Canadian Navy in the context of "Omaha Beach"

The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counterblockade. The campaign peaked from mid-1940 to the end of 1943.

The Battle of the Atlantic pitted U-boats and other warships of the German Kriegsmarine (navy) and aircraft of the Luftwaffe (air force) against the Royal Navy, Royal Canadian Navy, United States Navy, and Allied merchant shipping. Convoys, coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union, were protected for the most part by the British and Canadian navies and air forces. These forces were aided by ships and aircraft of the United States beginning on 13 September 1941. The Germans were joined by submarines of the Italian Regia Marina (royal navy) after Germany's Axis ally Italy entered the war on 10 June 1940.

Ship camouflage is a form of military deception in which a ship is painted in one or more colors in order to obscure or confuse an enemy's visual observation. Several types of marine camouflage have been used or prototyped: blending or crypsis, in which a paint scheme attempts to hide a ship from view; deception, in which a ship is made to look smaller or, as with the Q-ships, to mimic merchantmen; and dazzle, a chaotic paint scheme which tries to confuse any estimate of distance, direction, or heading. Counterillumination, to hide a darkened ship against the slightly brighter night sky, was trialled by the Royal Canadian Navy in diffused lighting camouflage.

Ships were sometimes camouflaged in classical times. Mediterranean pirate ships were sometimes painted blue-gray for concealment. Vegetius records that Julius Caesar's scout ships were painted bluish-green when gathering intelligence along the coast of Britain during the Gallic Wars. Ships were sometimes painted deceptively during the Age of Sail, while both sides in the American Civil War camouflaged their ships, whether to run blockades or for night reconnaissance.

Seaman is a military rank used in many navies around the world. It is considered a junior enlisted rank and, depending on the navy, it may be a single rank on its own or a name shared by several similarly junior ranks.

In the Commonwealth, it is the lowest rank in the navy, except in Canada where the Royal Canadian Navy now uses the gender-neutral title sailor in English and matelot in French. In the United States, it refers to the three lowest ranks of the U.S. Navy and U.S. Coast Guard. The equivalent of the seaman is the matelot in French-speaking countries, and Matrose in German-speaking countries.

The Canadian Armed Forces (CAF; French: Forces armées canadiennes, FAC) are the unified military forces of Canada, including sea, land, and air commands referred to as the Royal Canadian Navy, Canadian Army and the Royal Canadian Air Force. Under the National Defence Act, the Canadian Armed Forces are an entity separate and distinct from the Department of National Defence (the federal government department responsible for the administration and formation of defence policy), which also exists as the civilian support system for the forces.

The commander-in-chief of the Canadian Armed Forces is Charles III, who is represented by the Governor General. The chief of the Defence Staff is the professional head of the Canadian Armed Forces, who under the direction of the minister of national defence and together with the assistance of the Armed Forces Council, manages the operations of the Canadian Armed Forces.

The Halifax-class frigate, also referred to as the City class, is a class of multi-role patrol frigates that have served the Royal Canadian Navy since 1992. The class is the outcome of the Canadian Patrol Frigate Project, which dates to the mid-1970s. HMCS Halifax was the first of an eventual twelve Canadian-designed and Canadian-built vessels which combine traditional anti-submarine capabilities with systems to deal with surface and air threats as well. Ships of the class are named after capital cities of Canadian provinces (St. John's, Halifax, Charlottetown, Fredericton, Québec City, Toronto, Winnipeg, and Regina), the capital of Canada, Ottawa, and the major cities of Calgary, Montreal, and Vancouver.

In 2007, the Government of Canada announced a planned refit of the Halifax class which is known as the Halifax Class Modernization Project (HCMP) of which the Frigate Equipment Life Extension (FELEX) project is a part. In November 2008, a Lockheed Martin Canada-led team including Saab AB, Elisra, IBM Canada, CAE Professional Services, L-3 Electronic Systems and xwave, was awarded the contract. The construction phase of the program was completed in November 2016. As of May 2021, the Halifax-class modernization program was being closed out, but full operational capacity was reached on 31 January 2018.

The Kingston class consists of 12 coastal defence vessels operated by the Royal Canadian Navy. The class is the name for the Maritime Coastal Defence Vessel Project (MCDV). These multi-role vessels were built and launched from the mid- to late-1990s and are crewed by a combination of Naval Reserve and Regular Force personnel. The main missions of the vessels are reservist training, coastal patrol, minesweeping, law enforcement, pollution surveillance and search and rescue. The multi-purpose nature of the vessels led to their mixed construction between commercial and naval standards. The Kingston class is split between the east and west coasts of Canada and regularly deploy overseas to West Africa, Europe, Central America and the Caribbean.

In July 2025, the Royal Canadian Navy announced that the Kingston class will begin to be paid off and retired starting in late 2025, with an intended replacement in the planning stage.

The Upholder/Victoria-class submarines, also known as the Type 2400 (due to their displacement of 2,400 tonnes), are a class of diesel-electric submarines built in the United Kingdom in the 1980s to supplement the nuclear submarines in the Submarine Service of the British Royal Navy.

The boats were originally named the Upholder class, after the most renowned vessel of the former U class. Their British service life was short, with the vessels being decommissioned in 1994. After an unsuccessful bid to transfer these submarines to the Pakistan Navy in 1993–1994, the Canadian government eventually purchased the submarines and a suite of trainers from the Royal Navy for Canadian Forces Maritime Command (renamed to Royal Canadian Navy in 2011) to replace their decommissioned Oberon-class submarines in 1998.

Harry DeWolf-class offshore patrol vessels are warships of the Royal Canadian Navy (RCN) built within the Government of Canada Arctic and Offshore Patrol Ship (AOPS) procurement project, part of the National Shipbuilding Strategy. In July 2007 the federal government announced plans for acquiring six to eight icebreaking warships for the RCN.

The vessels are modelled on the Norwegian Coast Guard NoCGV Svalbard and as of 2007 were projected to cost CA$3.5 billion to construct with a total project procurement budgeted to cost $4.3 billion in order to cover maintenance over the 25-year lifespan of the vessels. In 2018 it was reported that the cost of the first six ships had increased by $810 million over previous projections. In 2023 it was reported that the cost for the first six ships had increased by a further $780 million and that of the two envisaged vessels for the Coast Guard by an additional $100 million.