Among the convoys "Emerald" escorted was the first Canadian troop convoy, in November 1939, when 7,500 troops reached Britain without incident. Convoy duty continued through the bitter winter of 1939/40. Agar's tour of duty as captain of the "Emerald" was completed in June 1940 after escorting a contingent of Canadian soldiers in the SS "Empress of Australia" to occupy Iceland. In the Clyde he handed over command of his beloved ship and departed with the cheers of his officers and crew ringing in his ears. He was then assigned to command the destroyer leader as head of the 16th Destroyer Flotilla based at Harwich. It was the first assignment in six months on temporary duty.