HMCS Toronto (K538)

The River class was a class of 151 frigates launched between 1941 and 1944 for use as anti-submarine convoy escorts in the North Atlantic. The majority served with the Royal Navy and Royal Canadian Navy (RCN), with some serving in the other Allied navies: the Royal Australian Navy (RAN), the Free French Naval Forces, the Royal Netherlands Navy and, post-war, the South African Navy.

The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against France. The modern Royal Navy traces its origins to the early 16th century; the oldest of the UK's armed services, it is consequently known as the Senior Service.

The Flower-class corvette was a British class of 294 corvettes used during World War II by the Allied navies particularly as anti-submarine convoy escorts in the Battle of the Atlantic. Royal Navy ships of this class were named after flowers.

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is 242,495 square kilometres (93,628 sq mi), with an estimated 2023 population of over 68 million people.

HMCS Valleyfield was a River-class frigate that served with the Royal Canadian Navy during the Second World War. She served primarily as a convoy escort in the Battle of the Atlantic. She was torpedoed and sunk in May 1944, the only River-class frigate lost by the RCN. She was named for Salaberry-de-Valleyfield, Quebec.

The Hedgehog was a forward-throwing anti-submarine weapon that was used primarily during the Second World War. The device, which was developed by the Royal Navy, fired up to 24 spigot mortars ahead of a ship when attacking a U-boat. It was deployed on convoy escort warships such as destroyers and corvettes to supplement the depth charges.

The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes, which are Superior, Michigan, Huron, Erie, and Ontario and are in general on or near the Canada–United States border. Hydrologically, lakes Michigan and Huron are a single body joined at the Straits of Mackinac. The Great Lakes Waterway enables modern travel and shipping by water among the lakes.

The St. Lawrence River is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a roughly northeasterly direction, into the Gulf of St. Lawrence, connecting the North American Great Lakes to the North Atlantic Ocean, and forming the primary drainage outflow of the Great Lakes Basin. The river traverses the Canadian provinces of Ontario and Quebec, as well as the U.S. state of New York, and demarcates part of the international boundary between Canada and the United States. It also provides the foundation for the commercial St. Lawrence Seaway.

The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of its active battle fleet alone exceeding the next 13 navies combined, including 11 allies or partner nations of the United States as of 2015. It has the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction, and five other carriers planned. With 336,978 personnel on active duty and 101,583 in the Ready Reserve, the United States Navy is the third largest of the United States military service branches in terms of personnel. It has 290 deployable combat vessels and more than 2,623 operational aircraft as of June 2019.

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.

Royal Canadian Navy base HMCS Protector, also known as the Point Edward Naval Base, was located next to Sydney Harbour, on Nova Scotia's Cape Breton Island. It was founded in 1940 and used by the navy during the Second World War. It was mainly used to provision, protect and repair the various merchant marine convoys to Quebec, Halifax, and the United Kingdom. It was a main combat zone during the Battle of the St. Lawrence and the more general Battle of the Atlantic. It continued to be utilized during the Cold War's early stages. It was decommissioned in 1964 and became the initial facility to house the Canadian Coast Guard College that same year. Currently, the Sydport Industrial Park utilizes the base's former piers and land.

The Battle of the St. Lawrence involved marine and anti-submarine actions throughout the lower St. Lawrence River and the entire Gulf of Saint Lawrence, Strait of Belle Isle, Anticosti Island and Cabot Strait from May–October 1942, September 1943, and again in October–November 1944. During this time, German U-boats sank over 20 merchant ships and four Canadian warships. There were several near-shore actions involving the drop of German spies, or the attempted pickup of escaping prisoners of war. Despite the 23 ships lost, this battle marked a strategic victory for Canadian forces as ultimately they managed to disrupt U-boat activity, protect Canadian and Allied convoys, and intercept all attempted shore operations. This marked the first time that a foreign power had inflicted casualties in Canadian inland waters since the US incursions in the War of 1812.

HMCS Magog was a River-class frigate that served in the Royal Canadian Navy (RCN) during the Second World War. She was used primarily as a convoy escort. On 14 October 1944, she was torpedoed by U-1223. She survived the attack, was towed to port and declared a constructive total loss. Magog was named for the town of Magog, Quebec.

HMCS Shawinigan was a Flower-class corvette that served with the Royal Canadian Navy during the Second World War. She served primarily in the Battle of the Atlantic protecting convoys. She was sunk in 1944. She was named for Shawinigan, Quebec.

The North Atlantic Treaty Organization, also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two North American. Established in the aftermath of World War II, the organization implemented the North Atlantic Treaty, signed in Washington, D.C., on 4 April 1949. NATO is a collective security system: its independent member states agree to defend each other against attacks by third parties. During the Cold War, NATO operated as a check on the perceived threat posed by the Soviet Union. The alliance remained in place after the dissolution of the Soviet Union and has been involved in military operations in the Balkans, the Middle East, South Asia, and Africa. The organization's motto is animus in consulendo liber.

HMCS Penetang was a River-class frigate that served in the Royal Canadian Navy from 1944 to 1945 during the Second World War. She fought in the Battle of the Atlantic as a convoy escort. She was recommissioned and served as a Prestonian-class frigate from 1954 to 1956. She was named for Penetanguishene, Ontario.

The Royal Norwegian Navy is the branch of the Norwegian Armed Forces responsible for naval operations of Norway. As of 2008, the Royal Norwegian Navy consists of approximately 3,700 personnel and 70 vessels, including 4 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support vessels and 2 training vessels. It also includes the Coast Guard.