Intended as a shore bombardment vessel, M27's primary armament was a single 9.2 inch Mk VI gun removed from the Edgar-class cruiser HMS Theseus.

She was equipped with a four shaft Bolinder two cylinder semi-diesel engine with 560 horse power that allowed a top speed of eleven knots.

M27 next saw service, along with five other monitors (M23, M25, M31, M33 and HMS Humber), which were sent to Murmansk in May 1919 to relieve the North Russian Expeditionary Force.

In June, 1919, M27 moved to Archangel and her shallow draught enabled her to travel up the Dvina River to cover the withdrawal of British and White Russian forces.

M27 and her sister ship M25 were unable to be recovered when the river level fell and were scuttled on 16 September 1919 after running aground.