'FCM' was the designation of Allied military convoys (together with a numerical suffix) plying the route from the Seine Bay in northern France to the south-western UK, and as such reciprocals of the 'ECM' series (June/July 1944).

The convoys were designed to return empty vehicle and equipment vessels from the 'Overlord' lodgement area to British ports for reloading.

The series began with FCM.1 of 11/12 June from the Seine Bay to Falmouth with 12 or 13 'Liberty' ships in the form of the 7,191-ton US Benjamin Hawkins, 7,181-ton US Charles M. Hall, 7,176-ton US Charles Sumner, 7,176-US Clara Barton, 7,176-ton US Edwin Abbey, 7,244-ton US George E. Pickett, 7,200 US Horace Gray, 7,176-US Jedediah S. Smith, 7,225-ton John S. Mosby, 7,176-ton US Lucy Stone, 7,181-ton US Robert E. Peary and probably the 7,176-ton US Henry S. Lane, escorted by the British sloop Lapwing.

The last of the series was FCM.28 that departed the Seine Bay on 9 July with 12 US 'Liberty' ships in the form of Edward D. White, Ezra Weston, Francis Drake, George Dewey, George Steers, James Caldwell, Jane Long, John A. Campbell, Joseph E. Johnston, Josiah Nelson Cushing, Julius Rosenwald and Samuel Colt.