The Canadian Navy was born when, after much debate, the Canadian Parliament passed the Naval Service Act, which came into effect on May 4, 1910. Officially known as the Naval Service Act of Canada, the new entity created a permanent volunteer force, which included a reserve. The Act also provided for the establishment of a naval college and in 1911 the Royal Naval College of Canada was established at Halifax, Nova Scotia but was later moved to Esquimalt, BC as a result of the 1917 Halifax explosion. The Royal Canadian Naval Volunteer Reserve was set up in 1913.

In its early years, Canada’s navy featured a single cruiser patrolling the waters of the west and east coast. The British cruiser HMCS Rainbow was the first ship commissioned into the Canadian Navy when it sailed into Esquimalt, B.C. on November 7, 1910. Her duties included fishery patrols and training. On Trafalgar Day, October 21, 1910, the second ship to join the Canadian Navy, the HMCS Niobe sailed into Halifax. (Canada’s Navy has operated five cruisers since 1910. In addition to the HMCS Rainbow and HMCS Niobe there were HMCS Aurora, HMCS Quebec(Uganda) and HMCS Ontario, the last cruiser in service which was paid off in October 1958.)

The Naval Service of Canada became the Royal Canadian Navy on January 30, 1911, although permission to use the Royal prefix was not granted by King George V until six months later.

Growth of the Navy was limited over the next several years due to political differences in Parliament, however, two submarines were commissioned into the RCN on August 7, 1914, as the First World War loomed. CC1 and CC2, Canadian C class subs, purchased by the premier of British Columbia from a shipyard in Washington, were later sold to the federal government and commissioned into wartime service. Sailors at this time were free to join either the British or Canadian navies – with many recruits choosing the former – and by the end of 1914 the RCN had about 3,600 recruits.

At the start of World War 1 the RCN had six Destroyers and a few other smaller ships.  By the end of the war the Navy had 2 small escort carriers, five cruisers, 28 destroyers, 70 frigates, 121 Corvettes (a small antisubmarine warship),  and 104 other support ships.

At the end of World War One much of the Canadian military forces had disipated.  Without an existing threat to the Empire or to Canada, as the end of the War had removed much of the latent hostility that had built up with the USA.  Much of the whole undefended border ideal was a modern invention.  Until World War One there were still plans in the Canadian Government files on how to defend the country from an invasion by the USA.