[1] The ship was built in 1885 by famed shipbuilders Laird Brothers Ltd of Birkenhead and delivered to the Liverpool company Liverpool Screw Towing & Lighterage Co Ltd.[2] At the outbreak of World War I the ship was hired by the British Royal Navy on 11 August 1914 and was later purchased outright on 4 November 1915.

[2] In 1915 the Blackcock along with five other tugboats (Liverpool's Sarah Joliffe and T. A. Joliffe, and Danube II, Southampton and Revenger from the Thames fleet) were ordered to tow the naval monitors HMS Severn and HMS Mersey from the UK to the Rufiji River delta in German East Africa.

They were not called upon, but according to Commander in Chief, Vice-Admiral Herbert King-Hall, the example the tugs "set was most praiseworthy.

"[4] On 17 January 1918 the ship, commanded by Lieutenant Robert Weir, set off on a mission to deliver supplies and passengers from Vardø, Norway to Murmansk, Russia.

[2] At the town a rescue party made up of dog sleds returned to the tug and got the rest of the crew.