Veterans, current service men and women, politicians and dignitaries have commemorated the single longest battle of the Second World War.
The names of ships lost at sea between 1939 and 1945 were read out on Sunday as the Battle of the Atlantic was remembered on Parliament Hill.
Several similar ceremonies were held across the country as people gathered to lay wreaths to mark the 71st anniversary of the battle.
Defence Minister Rob Nicholson and Chief of Defence Staff General Tom Lawson were among the dignitaries who attended the ceremony in Ottawa.
A bell rang each time the name of a ship lost during the battle was read out.
The Battle of the Atlantic began on Sept. 3, 1939, when the Montreal-bound passenger ship SS Athenia was sunk by a German submarine west of Ireland, killing 188 people, including four Canadians.
By the time the war was over, more than 3,000 sailors and merchant seamen had lost their lives delivering supplies across the Atlantic Ocean to Britain.
When the battle began, Canada's navy had only 13 ships, including a half dozen destroyers.
But the Canadian navy fleet grew to 373 fighting vessels in the six years that followed, making it the world's third largest.