'COC' was the designation of Allied military convoys (together with a numerical suffix) using coasting vessels on the route from ports in southern England to ports in Brittany on the northern coast of France for the delivery of military supplies (November 1944/May 1945).
The first of the series was COC.1 which departed Plymouth on 2 November 1944 for St Malo with the 744-ton British Gateshead and 692-ton British Kenrix, and the last was COC.174 from Falmouth to Granville on 23/24 May 1945 with the 1,126-ton British Majorca.