On February 13, 2025, the Royal Canadian Navy (RCN) celebrated a significant milestone when HMCS Corner Brook, one of Canada’s four Victoria-class submarines, returned to sea for the first time since 2011. This event marked the end of a 14-year saga of damage, delays, and determined repair efforts, restoring a critical asset to Canada’s maritime defense capabilities.
HMCS Corner Brook, originally commissioned as HMS Ursula in the Royal Navy in 1992, was acquired by Canada in 1998 as part of a controversial purchase of four Upholder-class submarines. Renamed and reclassified as a Victoria-class vessel, she entered Canadian service in 2003. Designed as a long-range hunter-killer submarine, Corner Brook was intended to bolster Canada’s ability to patrol its vast coastlines and participate in international naval operations. However, her career has been anything but smooth.
The submarine’s troubles began in earnest on June 4, 2011, during a training exercise off Vancouver Island. While submerged at a depth of 45 meters in Nootka Sound, Corner Brook struck the ocean floor, sustaining significant damage to her bow. A subsequent board of inquiry attributed the incident to human error by her Commanding Officer. Although the pressure hull remained intact and the crew was unharmed, the collision left a gaping four-by-four-meter hole in the fiberglass sonar dome, raising concerns about the vessel’s future viability.
Following the grounding, Corner Brook returned to Esquimalt, British Columbia, under her own power, but her operational days were far from resuming. Initial assessments in 2012 revealed the extent of the damage, prompting fears that the submarine might be beyond repair. However, the RCN opted to integrate the necessary fixes into a pre-planned Extended Docking Work Period (EDWP), a comprehensive overhaul scheduled to begin in July 2014. The goal was not only to repair the damage but also to modernize the submarine with upgraded systems, including the advanced BQQ-10 sonar system.
What was initially projected as a two-and-a-half-year maintenance period stretched into a much longer ordeal. In April 2019, while still in drydock at Victoria Shipyards, a fire broke out onboard. Though quickly extinguished, the incident added further delays. Then, in March 2020, a pressure test mishandled by contractor Babcock Canada went awry. Attempting to speed up the draining of a ballast tank, the test team over-pressurized it, causing a rupture. An internal Defence Department report later deemed some of the resulting damage permanent, noting that a full repair would be neither practical nor economical. Instead, the Navy accepted a compromise, and planned for the submarine to return to service with residual risks to be monitored.
Despite these setbacks, Corner Brook’s refit progressed. By June 2021, she was finally undocked and returned to the water at Esquimalt Graving Dock, transported via the lift barge Seaspan Careen to Ogden Point. Sea trials and a critical camber dive in October 2022 confirmed the functionality of her systems, paving the way for her eventual return to full service.
The culmination of this long effort came in February 2025, when HMCS Corner Brook embarked on her first operational voyage in over a decade. The RCN hailed the achievement as a “critical milestone” for the Canadian Submarine Force.
It is not clear when Corner Brook will be given important taskings, such as resuming her role in covert patrols, national defense, and international exercises. However, now equipped with modernized systems, she is described by the RCN as the most advanced submarine in Canada’s fleet—a significant upgrade from her pre-2011 configuration.