Hundreds of sailors and cadets commemorated the Battle of the Atlantic today. Each year on the first Sunday in May, Canada and its naval community commemorate those lost at sea in the longest single campaign of the Second World War. The Battle of the Atlantic was a pivotal struggle during the Second World War, lasting from September 1939 to May 1945, which was fought by the men and women of the Royal Canadian Navy, the Canadian Merchant Navy, and the Royal Canadian Air Force. With this success came a high cost. The RCN lost 33 vessels and suffered over 2,000 fatalities; the merchant navy lost over 70 ships and over 1,700 fatalities; and the Royal Canadian Air Force lost more than 900 aircrews.