She is the former Royal Navy Upholder-class submarine HMS Ursula (S42), purchased from the British at the end of the Cold War.

They are equipped with two Paxman Valenta 1600 RPS SZ diesel engines each driving a 1.4-megawatt (1,900 hp) GEC electric alternator with two 120-cell chloride batteries.

In British service, the submarines were equipped with 14 Tigerfish Mk 24 Mod 2 torpedoes and four UGM-84 Sub-Harpoon missiles.

[3] In 2014, the Government of Canada purchased 12 upgrade kits that will allow the submarines to fire the Mk 48 Mod 7AT torpedoes.

[8] Looking to discontinue the operation of diesel-electric boats, the British government offered to sell Ursula and her sister submarines to Canada in 1993.

The former Ursula was handed over to the Canadian Forces on 21 February 2003, and commissioned as HMCS Corner Brook on 29 June 2003.

[8] After commissioning, Corner Brook was deployed on the east coast of Canada, based out of Halifax, Nova Scotia.

[13] During the exercise, which occurred in the Baltic region, Corner Brook successfully closed with the aircraft carrier HMS Illustrious without being detected.

[13] The submarine returned to Canada, and in August, she participated in Operation Nanook, a sovereignty exercise held in and around Iqaluit and the Baffin Island coastal and Hudson Strait areas.

[10] In February 2008, Corner Brook departed from Halifax during a snowstorm for a three-month deployment to the Caribbean Sea.

As part of the deployment, the submarine operated with the United States Joint Interagency Task Force South, which attempts to counter drug trafficking, people smuggling and piracy in the region.

[14] In January 2009, Corner Brook was the target for submarine detection exercises performed by HMCS Halifax and Montréal.

[17] During August, the submarine was involved in Operation Nanook 2009 conducting covert surveillance patrols in the vicinity of Baffin Island.

The submarine collided with the sea floor in 45 metres (148 ft) of water while travelling at a speed of 5.9 knots (11 km/h).

[22] As of July 2014, Corner Brook began her extended docking work period (EDWP)[10] that was expected to take until 2017 to complete.