On a plate a caribou rampant proper holding an escutcheon Or edged Gules semé of bezants and charged with a quatrefoil slipped Vert, all within an annulus charged with a rope Or issuant from in chief a billet fesswise Vert edged Or inscribed with the name of the ship in letters Argent, surmounted in base by three maple leaves, and ensigned by a naval crown Or its sails Argent;
(Glossary of Heraldic Terms)
The caribou refers to the SS Caribou, the ferry on which Sub-Lieutenant Margaret Brooke, a nurse serving with the Royal Canadian Navy, was travelling when it was torpedoed by a U-Boat in 1942. Brooke was honoured for her bravery in attempting to save the life of her colleague Sub-Lieutenant Agnes Wilkie. The four-leaf clover was a good-luck charm carried by Brooke during the ordeal. The shield symbolizes protection, and its colours, green and yellow, are those of Saskatchewan, Margaret Brooke’s home province. The border of the shield alludes to the deep pink ribbon of the Order of the British Empire, of which Brooke was made a Member in recognition of her bravery. The white background refers to the Arctic environment in which HMCS Margaret Brooke will operate.
Arctic and Offshore Patrol Ship (AOPS)