HMCS Arrowhead

In Canadian service the vessels were altered due to experience with the design's deficiencies. The galley was moved further back in the ship and the mess and sleeping quarters combined. A direction-finding set was installed and enlarged bilge keels were installed to reduce rolling.[10] After the first 35–40 corvettes had been constructed, the foremast was shifted aft of the bridge and the mainmast was eliminated. Corvettes were first fitted with basic SW-1 and SW-2 CQ surface warning radar, notable for their fishbone-like antenna and reputation for failure in poor weather or in the dark. The compass house was moved further aft and the open-type bridge was situated in front of it. The ASDIC hut was moved in front and to a lower position on the bridge. The improved Type 271 radar was placed aft, with some units receiving Type 291 radar for air search. The minesweeping gear, a feature of the first 54 corvettes, was removed.[11] Most Canadian Flower-class corvettes had their forecastles extended which improved crew accommodation and seakeeping. Furthermore, the sheer and flare of the bow was increased, which led to an enlarged bridge. This allowed for the installation of Oerlikon 20 mm (0.8 in) cannon, replacing the Browning and Vickers machine guns.[12] Some of the corvettes were rearmed with Hedgehog anti-submarine mortars.[13] The complements of the ships grew throughout the war rising from the initial 47 to as many as 104.[12]

After commissioning Arrowhead sailed to Sunderland in January 1941 to fully fit out which took two months.[16] There were delays in the arrival of essential equipment for the British corvettes in Canada and some of them sailed without their main armament as they sailed from Canadian dockyards as soon as they were fit for the Atlantic crossing. Due to a lack of ships and a surplus of manpower, the Royal Canadian Navy offered to crew the ships until mid-1941 when enough of the Canadian corvettes would become available. Then in April 1941, the British Admiralty requested that Canada take over the ships permanently.[18] Arrowhead worked up at Tobermory and joined EG-4 of the Royal Navy's Iceland Command taking part in the Battle of the Atlantic. The ship commissioned into the Royal Canadian Navy on 15 May 1941.[16]

In June 1941, after commissioning in the RCN, Arrowhead joined the Newfoundland Escort Force and spent the majority of 1941 escorting convoys from St. John's to Iceland.[16] On 1 September 1941, the convoy escort groups (EG) were re-organised and the ship was made part of EG 18. In early September convoy SC 43 which EG 18 was escorting was detoured south to avoid the German wolfpack "Markgraf". On 18 September, the convoy SC 44 came under attack by German U-boats. Initial German attacks sank four of the merchant vessels. Arrowhead is one of three warships sent to reinforce the convoy, which prevent further sinkings.[19]

In late December, Arrowhead was sent to Charleston for a refit. She returned to Halifax in February 1942 and did one more cross-Atlantic convoy before being reassigned to Western Local Escort Force (WLEF). In July she joined the Gulf Escort Force and participated in the Battle of the St. Lawrence.[16] On 31 August the U-boats U-165 and U-517 entered the St. Lawrence River. On 6 September, the convoy QS 33, escorted by Arrowhead, HMCS Truro, two motor launches and the armed yacht HMCS Raccoon was spotted by U-517. Arrowhead detected U-517 and attempted to sink the submarine unsuccessfully. However, while dealing with U-517, U-165 snuck past the escort and sank three ships comprising 4,729 GRT and Raccoon. On 15 September U-517 attacked a second convoy escorted by Arrowhead, the minesweeper HMCS Vegreville and three motor launches. U-517 sank two ships from the convoy. The following day, the convoy came under attack by U-165 and sank two more ships for a total loss of 10,292 GRT along with another merchant vessel that was torpedoed but remained afloat.[20]

Arrowhead spent the final months of 1942 bouncing around commands, joining Halifax Force in October. While with Halifax Force, Arrowhead was one of three warships tasked with escorting NL 9. The U-boat U-69 attacked the convoy, sinking the ferry Caribou.[20] The corvette returned to WLEF at the end of November and stayed with the unit until August 1944. In June 1943, when WLEF introduced dedicated escort groups, Arrowhead was first assigned to group W-7 before transferring to W-1 in December.[16]

During her period with WLEF, Arrowhead had two major refits, one in Charleston in the spring of 1943 and one in Baltimore in May 1944 where her forecastle was extended. After returning to service she was assigned to Quebec-Labrador convoys in September 1944. In December of that year, Arrowhead was reassigned to Western Escort Force's Escort Group W-8 and used on the "Triangle Run" between Boston/New York, Halifax and St. John's until May 1945.[16]

Arrowhead was assigned to convoy HX 358 with three other loaned corvettes, Eyebright, Hepatica and Trillium. After arrival at Milford Haven, on 27 June 1945 she was paid off and returned to the Royal Navy.[16] For service in the Battle of the Atlantic, Arrowhead earned the battle honour "Atlantic 1941–45"[21] and earned the battle honour "Gulf of St. Lawrence 1942, 1944" for service in the Battle of the St. Lawrence.[22]

In 1947 Arrowhead was sold for conversion to a whale-catcher with a gross register tonnage of 757 tons, emerging in 1948.[23] She was renamed Southern Larkspur. Eventually, the vessel was broken up at Odense, Denmark in December 1959 by H.I. Hansen.[16][23]