Vigilant, designed as an armed patrol vessel for service on the Great Lakes, was of steel construction and fitted with a ram bow.

[2] Vigilant, described as the "first modern warship to be built in Canada", was acquired for patrol service on the Great Lakes to replace the aging CGS Petrel.

[1][2] The vessel was constructed by Polson Iron Works Limited at their shipyard in Toronto and was launched on 11 September 1904, and completed later in the year.

[5] Vigilant was credited at the time by the Minister of Marine and Fisheries, Louis-Philippe Brodeur as being the nucleus of the future Royal Canadian Navy.

[2] On 7 June 1905 Vigilant collided with the 12 gross register tons (GRT) fishing steamer Grace M. six miles (9.7 km) east of Middle Island in Lake Erie.