Destroyers
	Corvettes: The Early Corvettes were the Toughest
	Minesweepers
	Frigates
	Fairmile Motor Launch
	Motor Torpedo Boat
	Landing Crafts

Building corvettes at the Kingston Shipbuilding Co. in Kingston, Ontario, August 1943. National Archives of Canada, PA-052613.

When the war breaks out, Allied navies are facing a formidable foe. Since 1934, Adolph Hitler has been directing considerable energy and countless resources towards rebuilding the German war navy. The Allies must now urgently increase their fleets, as well as replace losses resulting from mines, torpedoes, encounters with enemy ships, aerial bombings, accidents and storms.

The Royal Canadian Navy (RCN), which started the war with only 13 vessels, had 450 ships in all, plus many smaller auxiliary units, when WWII ended. This 1945 figure breaks down as follows: 2 cruisers, 17 destroyers, 68 frigates, 112 corvettes, 67 minesweepers, 12 escort ships, 75 Fairmile motor launches, 9 motor torpedo boats, 12 armoured yachts and vessels of other types. This impressive fleet made the RCN the world's fourth naval power.

But to reach that goal within such a short period, the RCN had to make use of all available resources: yachts were commandeered and armed to serve on anti-submarine patrols. Some destroyers were supplied by the Royal Navy, others by the U.S. Navy in exchange for the right to use Canadian bases. Some Royal Navy units, including aircraft carriers Nabob and Puncher, were placed under Canadian command and manned with Canadian crews when Britain found herself short of sailors.

But most Canadian warships had to be built. Starting in 1940, shipyards, which had been declining during the Depression, increase their production tenfold in order to provide the RCN with corvettes, minesweepers, and frigates. It is on board of corvettes, those small, sturdy and cheap vessels, apparently ill-suited to wage war on the high seas, that Canadian sailors will face Germany's formidable U-boats during the worst months of the Battle of the Atlantic.

At any given time, only part of a war fleet is available for naval operations, as ships must often be dry-docked - at times for long stretches - to repair damages resulting from encounters with the enemy or adverse weather. In addition, crews need rest and training. In the extremely harsh conditions of the first years of the Battle of the Atlantic, barely two thirds of the fleet could be used for military operations at any given time, and that ratio was even lower during winter months.

The RCN's main vessel types
Destroyers
Corvettes
Minesweepers
Frigates
Fairmile Motor Launches
Motor Torpedo Boats
Landing Craft

U-889 surrendering to the Royal Canadian Navy off Shelburne, Nova Scotia, in May 1945. Photo by R.G. Arless. Department of National Defence / National Archives of Canada, PA-134333.

Enemy Warships
In 1939, the Kriegsmarine's striking power is impressive, due among other things to its daunting battleships Bismarck and Tirpitz, and to the pocket battleships Deutschland, Admiral Scheer and Admiral Graf Spee. On several occasions, Canadian destroyers took part in Royal Navy operations against German battleships. HMCS Assiniboine was part of the escort of British ships that inflicted major damage to Tirpitz in August 1944. The Royal Navy was the only naval power able to restrict German warships to the North Sea and did so during the whole war.

Used mostly for the protection of convoys, RCN ships face another Kriegsmarine weapon, maybe the most formidable one, the Unterseeboot or U-boat. During the Battle of the Atlantic, Allied warships were attacked by Type-VIIC U-boats, 67m-long submarines with a surface speed of 17.7 knots and an underwater speed of 7.6 knots. The VIIC is equipped with four torpedo tubes at the fore and one at the aft, carrying 14 torpedoes in all, and manned by a crew of 44 to 52. Near Canadian shores and along the routes used by convoys, the Allies fought the IXC/40, a long-range submarine, longer and faster than the VIIC. The IXC/40 carries 22 torpedoes, and with its 19 knot-speed, can escape a corvette. Fortunately, the most powerful of all U-boats, the Type XXI was not combat-ready before 1945, too late to prevent the Allies from winning the Battle of the Atlantic.