Cuban fishing vessels believed to be violating Canadian Coastal Fisheries Laws in the approaches to Halifax harbour. On 12 January 1977, Algonquin deployed for CARIBEX 1–77 Assiniboine, Protecteur and Margaree, part of the United States Navy (USN) exercise Springboard 77 in the Puerto Rican operating area. Algonquin was assigned flagship of First Canadian Destroyer Squadron. On 27 May 1978 Algonquin was awarded the L.W. Murray Trophy for gunnery excellence and the 20 Knot Mortar Firing Trophy, both of which were retained by Algonquin for the second year running. On 28 August, the ship departed Halifax for the NATO exercise Northern Wedding. On 26 September Algonquin assumed the role of flagship to the Canadian Commander of STANAVFORLANT from sister ship , and was one of a seven ship squadron. From 15–18 November, the ship was part of STANAVFORLANT and conducted anti-submarine warfare (ASW) operations in the Baltic Sea. She continued as part of the STANAVFORLANT force into 1979, tracking and shadowing Warsaw Pact submarines in the North Atlantic. 1980s A scheduled refit postponed to 1981 resulted in Algonquins exclusion in any national or NATO exercises. Algonquin presented the ASW Proficiency Shield and the 20 Knot Trophy. On 26 January, a fire, rated as "A" class, occurred in the forward decontamination compartment. The fire was believed to have been caused by toilet paper, stored temporarily in the space, coming into contact with a steam radiator. In November, the ship participated in ASW exercises, torpedo firings and pro-submarine exercises with the submarine . The postponed refit occurred from January–July 1981, noted to have been completed on time, as scheduled. Additions included Surface and Air Weapon Information System (SAWIS) performance monitoring equipment for the Gun/Missile Fire Control System and 84 tons of ballast in the aft section of the ship. The ship worked-up in August and September, and in November participated in the naval exercise MARCOT 2/81. Algonquin participated in two major deployments in 1982, beginning with CARIBOPS 82 for two months and then STANAVFORLANT for five months as flagship of the fleet. Algonquin took part in a search for an American A7 Aircraft believed to have crashed just north of Puerto Rico; no detail on the aircraft or search was provided. In February, during CARIBOPS 82, Algonquin was dispatched west of Martinique where the diving support vessel was drifting, having lost all propulsion. Proceeding with all dispatch, Algonquin met Cormorant the same day