HMCS Nipigon was an that served in the Royal Canadian Navy and later the Canadian Forces. She was the second Canadian naval unit to carry this name. Entering service in 1964, she was named for the Nipigon River that flows through Ontario. Nipigon served throughout the Cold War on the Atlantic coast of Canada. She was paid off in 1998 and sold for use as an artificial reef off the coast of Quebec. Design and description The Royal Canadian Navy had intended to place a six ship order under the of destroyer escorts; however, during the design phase, the last two vessels ordered were altered to the DDH design and were classed under the new Annapolis designation. The ships measured in length, with a beam of and a draught of . Initially, the ships displaced and had a complement of 228. The ships were powered by two Babcock & Wilcox boilers connected to the two-shaft English-Electric geared steam turbines providing . This gave the ships a maximum speed of . The ships were initially armed with two /50 caliber dual-purpose guns mounted in a single turret forward. The extra topweight of the helicopter required the return of the American Mk 33 3-inch gun over the heavier 3-inch/70 caliber guns used on the preceding class. The guns could fire 45 – 50 rounds per minute with a lifespan of 2,050 rounds. The guns were placed in a Mk 33 mount. The mounting allowed the guns to elevate from −15° to 85°. The elevation rate was 30° per second and train rate was 24° per second. The mounts could train 360°. For anti-submarine warfare, the ships were armed with a Mk 10 Limbo mortar. The Limbo was a British-designed three-barrel mortar capable of launching a projectile shell between . Placed on stabilized mountings, the projectiles always entered the water at the same angle. The total weight of the shell was . They also had a Mk.4 thrower with homing torpedoes. Initially the ships were outfitted with one SPS-12 air search radar, one SPS-10B surface search radar, and one Sperry Mk.2 navigation radar. For sensing below the surface, the class was given one SQS-501 high frequency bottom profiler sonar, one SQS-502 high frequency mortar control sonar, one SQS-503 hull mounted active search sonar and one SQS-504 VDS medium frequency active search sonar. For fire control purposes they were given one Mk 64 GFCS