On 12 November 1975, "Achilles" collided with the Greek tanker "Olympic Alliance" in heavy fog in the Dover Strait, causing a number of injuries aboard "Achilles" together with heavy damage to the frigate's bow, while a large oil slick was released from the tanker into the Channel. "Achilles" was under repair at Devonport Dockyard until March 1976, with her complete bow section needing to be replaced. The following year, "Achilles" joined the Fishery Protection Squadron during the Third Cod War with Iceland, spending one week on patrol. During that year also, HMS "Achilles" was covertly deployed to Belize during the Guatemalan emergency.