When the Canadian Naval Service was established in 1910 (soon renamed the Royal Canadian Navy) it inherited the Ship's Police system that was already well established in Britain's Royal Navy. The RCN Ship's Police branch predated the First World War and since its members (called Ship's Corporals and Masters-at-Arms) were specifically "rated" as tradesmen for these specialist duties they were arguably Canada's first permanent service police organization.
The Ship's Police system lasted only for the first 9 years of the RCN's existence, but from this organization was borne the better-known Regulating Branch which continued to provide certain types of policing support to Canada's navy for the next five decades.
Learn more about the Ship's Police in the early RCN and view additional photos here.
Postcard from 1910 that caricatures a member of the Ship's Police (Credit: Ernest Ibbetson)