[1] The U-class were War Emergency Programme destroyers, intended for general duties, including use as anti-submarine escort, and were to be suitable for mass-production.

615 tons of oil were carried, giving a range of 4,675 nautical miles (5,380 mi; 8,658 km) at 20 knots (23 mph; 37 km/h).

At the same time, the relatively recent War Emergency destroyers, with their low-angle guns and basic fire control systems, were considered unsuitable for modern warfare, so it was decided to convert these obsolete destroyers into fast escorts, acting as a stop-gap solution until new-build ships, such as the Type 12 frigates could be built in sufficient numbers.

[13][14] The revised ships had a much reduced gun armament of one twin 4-inch (102 mm) anti aircraft mount aft of the main superstructure and one twin Bofors mount, but anti-submarine equipment was as fitted to the Type 12s, with Ursa being fitted with two Limbo anti-submarine mortars, directed by Type 170 and 172 sonar.

[23][24] In early August 1944, operations switched to the French Atlantic coast, with the Home Fleet deploying cruiser and destroyer forces to the Bay of Biscay to prevent attempts of German surface units in the French Atlantic ports to escape back to Germany.

[25] On the night of 14–15 August, Ursa together with the cruiser Mauritius and the Canadian destroyer Iroquois, attacked a German convoy, consisting of the aircraft repair ship Richthofen, Sperrbrecher 157, the torpedo boat T28 and the minesweepers M275 and M385 off Les Sables-d'Olonne.

[26][27] On the night of 22/23 August, Ursa, Mauritius and Iroquois ambushed two groups of German patrol boats (Vorpostenboot) off Audierne, sinking V702, V714, V717, V719, V720, V729 and V730.

[26][28][29] Ursa was refitted at Portsmouth in September–October 1944, before leaving for the Far East, rejoining the 25 Destroyer Flotilla at Trincomalee, Ceylon (now Sri Lanka) in November that year.

[31] On 4 January 1945, Ursa took part in Operation Lentil, a strike by aircraft from the carriers Indomitable Indefatigable and Victorious against oil refineries at Pangkalan Brandan, Sumatra.

[35] She arrived at Sliema Creek Malta, in company with sister ships Undine (Captain F), Ulysses and Urania.

In June–July 1956 she underwent a minor refit of approximately five weeks in Gibraltar, later going into the King George IV dry dock, with the whole squadron (and two minesweepers) for maintenance.

In November 1956, with the rest of the squadron, Ursa formed part of the Royal Navy's force used during the Suez Operation.

[citation needed] She again served in the Bahamas and West Indies in 1966 before paying off at Portsmouth on 28 October that year.