Hull classification symbol (Canada)

HMCS Cormorant was a diving support vessel that served in the Canadian Forces. She was equipped with two SDL-1 submersibles. The ship was the first in the Canadian Forces to have women assigned to their crew. Initially constructed as the trawler Aspa Quarto in 1965, the ship was acquired by the Canadian Forces in 1975 and renamed Cormorant. The vessel remained in service until 1997 when Cormorant was sold to a US buyer. The ship was laid up at Bridgewater, Nova Scotia in 2000 and was removed on 18 November 2020 to be scrapped in Sheet Harbour.

HMCS Bras d'Or was a hydrofoil that served in the Canadian Forces from 1968 to 1971. During sea trials in 1969, the vessel exceeded 63 knots, making her the fastest unarmed warship in the world at the time.

In the 18th century and most of the 19th, a sloop-of-war in the Royal Navy was a warship with a single gun deck that carried up to eighteen guns. The rating system covered all vessels with 20 guns and above; thus, the term sloop-of-war encompassed all the unrated combat vessels, including the very small gun-brigs and cutters. In technical terms, even the more specialised bomb vessels and fireships were classed as sloops-of-war, and in practice these were employed in the sloop role when not carrying out their specialised functions.

The Orca-class patrol vessels are a class of eight steel-hulled training and surveillance vessels in service with the Royal Canadian Navy (RCN) at Patrol Craft Training Unit (PCTU) Canadian Forces Base (CFB) Esquimalt. Based on the Australian Pacific-class patrol boat design, all of the Orca vessels were constructed by Victoria Shipyards between November 2004 and November 2008. In addition to carrying the RCN designation of patrol craft training (PCT), the Orca-class are not formally commissioned in the RCN and as such do not possess the His Majesty's Canadian Ship (HMCS) prefix.

The Isles-class trawlers were a class of naval trawler used by the Royal Navy, Royal Canadian Navy and Royal New Zealand Navy during World War II.

The Glen-class tug is a class of naval tugboat operated by the Royal Canadian Navy. Constructed in Canada, the class entered service between 1975 and 1977. The five vessels that comprise the class are split between the two major naval bases of the Royal Canadian Navy. The Royal Canadian Navy operated a fleet of tugboats during the Second World War which were also named the Glen class. The vessels of the current Glen class are each named after one of the vessels of the earlier class.

The Ville-class harbour tugboats are a class of tugboats employed by the Royal Canadian Navy.

The Fire-class fireboats/yard tractor tugs were two fireboats operated by the Royal Canadian Navy. The two vessels are CFAV Firebrand (YTR 562) and CFAV Firebird (YTR 561).

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.

An escort destroyer with United States Navy hull classification symbol DDE was a destroyer (DD) modified for and assigned to a fleet escort role after World War II. These destroyers retained their original hull numbers. Later, in March 1950, the post World War II ASW destroyer (DDK) classification was merged with the DDE classification, resulting in all DDK ships being reclassified as DDE, but again retaining their original hull numbers. On 30 June 1962, the DDE classification was retired, and all DDEs were reclassified as destroyers (DD). Escort destroyers should not be confused with the cheaper, slower, less capable, and more lightly armed World War II destroyer escorts.

The Restigouche-class destroyer was a class of seven destroyer escorts that served the Royal Canadian Navy and later the Canadian Forces from the late-1950s to the late-1990s. All seven vessels in the class were named after rivers in Canada.

Iroquois-class destroyers, also known as Tribal class or DDG 280 class, were a class of four helicopter-carrying, guided missile destroyers of the Royal Canadian Navy. The ships were named to honour the First Nations of Canada.

The Tribal class, or Afridi class, were a class of destroyers built for the Royal Navy, Royal Canadian Navy and Royal Australian Navy that saw service in World War II. Originally conceived during design studies for a light fleet cruiser, the Tribals evolved into fast, powerful destroyers, with greater emphasis on guns over torpedoes than previous destroyers, in response to new designs by Japan, Italy, and Germany. The Tribals were well admired by their crews and the public when they were in service due to their power, often becoming symbols of prestige while in service.

The G- and H-class destroyers were a group of 18 destroyers built for the Royal Navy during the 1930s. Six additional ships being built for the Brazilian Navy when World War II began in 1939 were purchased by the British and named the Havant class. The design was a major export success with other ships built for the Argentine and Royal Hellenic Navies. They were assigned to the Mediterranean Fleet upon completion and enforced the Non-Intervention Agreement during the Spanish Civil War of 1936–1939.

The Clemson class was a series of 156 destroyers which served with the United States Navy from after World War I through World War II.

HMCS Algonquin was a V-class destroyer, laid down for the Royal Navy as HMS Valentine (R17) and transferred to the Royal Canadian Navy on completion during the Second World War. She saw service in the Second World War escorting the aircraft carriers that bombed the Tirpitz in March 1944 and providing naval gunfire support to the Normandy landings. The destroyer was to participate in the Pacific Campaign but the war ended before her arrival in that theatre. Algonquin was converted in 1953 to a frigate and spent the majority of her remaining career in the Atlantic, being paid off in 1970.

The U and V class was a class of sixteen destroyers of the Royal Navy launched in 1942–1943. They were constructed in two flotillas, each with names beginning with "U-" or "V-". The hull was nearly identical to the preceding ships of the S and T classes, but the U and V class ships had different bridge and armament fits. The flotillas constituted the 7th Emergency Flotilla and 8th Emergency Flotilla, built under the War Emergency Programme. These ships used the Fuze Keeping Clock HA Fire Control Computer.

The C class was a class of 32 destroyers of the Royal Navy that were launched from 1943 to 1945. The class was built in four flotillas of 8 vessels, the "Ca", "Ch", "Co" and "Cr" groups or sub-classes, ordered as the 11th, 12th, 13th and 14th Emergency Flotillas respectively. The sub-class names are derived from the initial 2 letters of the member ships' names, although the "Ca" class were originally ordered with a heterogeneous mix of traditional destroyer names. A fifth flotilla, the "Ce" or 15th Emergency Flotilla, was planned but were cancelled in favour of the Weapon-class destroyers after only the first two ships had been ordered. The pennant numbers were all altered from "R" superior to "D" superior at the close of World War II; this involved some renumbering to avoid duplications.

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 Bangor-class minesweepers were a class of warships operated by the Royal Navy (RN), Royal Canadian Navy (RCN), Imperial Japanese Navy (IJN), and Royal Indian Navy (RIN) during the Second World War.

The Algerine-class minesweeper was a large group of minesweepers built for the Royal Navy (RN) and the Royal Canadian Navy (RCN) during the Second World War. 110 ships of the class were launched between 1942 and 1944.

The Bay-class minesweepers, also known as the Gaspé-class minesweepers, were a class of minesweepers operated by the Royal Canadian Navy (RCN) and Canadian Forces (CF) during the Cold War. Their design was similar to the British Ton-class minesweepers.

The Anticosti-class minesweepers were a class of minesweepers that served with the Canadian Forces from 1989–2000. The class consisted of two former oil rig supply vessels, Jean Tide and Joyce Tide. They were acquired by Maritime Command (MARCOM) and commissioned in May 1989 with Jean Tide becoming HMCS Anticosti (MSA 110) and Joyce Tide becoming HMCS Moresby (MSA 112). Once the Kingston-class coastal defence vessels became operational, the Anticosti class was discarded and the two ships returned to mercantile use.

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 mission of the vessels is to train reservists, coastal patrol, minesweeping, law enforcement, pollution surveillance and search and rescue duties. 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.

The Oberon class was a ship class of 27 British-designed submarines operated by five nations. They were designed as a follow-on from the Porpoise class; physical dimensions were the same but stronger materials were used in hull construction and improved equipment was fitted.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.

The Balao class was a successful design of United States Navy submarine used during World War II, and with 120 boats completed, the largest class of submarines in the United States Navy. An improvement on the earlier Gato class, the boats had slight internal differences. The most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames, which increased their test depth to 400 feet (120 m). Tang actually achieved a depth of 612 ft (187 m) during a test dive, and exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer.

Tench-class submarines were a type of submarine built for the United States Navy (USN) between 1944 and 1951. They were an improvement over the Gato and Balao classes, only about 35 to 40 tons larger, but more strongly built and with a slightly improved internal layout. One of the ballast tanks was converted to carry fuel, increasing range from 11,000 nautical miles to 16,000 nautical miles. This improvement was also made on some boats of the previous two classes. Further improvements were made beginning with SS-435, which are sometimes referred to as the Corsair class. Initial plans called for 80 to be built, but 51 were cancelled in 1944 and 1945 when it became apparent that they would not be needed to defeat Japan. The remaining 29 were commissioned between October 1944 (Tench) and February 1951 (Grenadier). The last submarine of the Tench class, as well as the last submarine which served during World War II, remaining in service with the U.S. Navy was USS Tigrone (AGSS-419) which was decommissioned on 27 June 1975.

The Upholder/Victoria-class submarines, also known as the Type 2400, are the class of the 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.