Ensigns and Jacks
On March 3, 1911, the RCN was authorized the use of the White Ensign, which remained the main identifying flag of the navy for the next 54 years. At the same time, the Canadian Blue Ensign was designated the jack of the RCN. However, because naval tradition dictates that the jack is worn at the ship's bow only when moored or on "dress ship" occasions, HMC ships normally had no distinctly Canadian flags when under way, the White Ensign being identical to the Royal Navy's ensign. Because of this, a tradition developed of painting a green maple leaf on ships' funnels to mark the ship as Canadian.
When British and Canadian foreign policies began to diverge in the 1950s (highlighted by the two countries' different roles in the Suez Crisis), having an ensign identical to the Royal Navy's became less satisfactory. In 1961, a policy of wearing the Canadian Red Ensign from the masthead (in addition to the Canadian Blue Ensign at the jack staff when appropriate, and the White Ensign at the ensign staff) was established. On February 15, 1965, the White, Blue, and Red ensigns were all replaced by the new National Flag of Canada, the Maple Leaf flag.
Read more about this topic: History Of The Royal Canadian Navy