From a very modest beginning in 1914 the Auxiliary Patrol grew to about 5,000 yachts, gunboats, trawlers, whalers, M.L.'s, drifters, etc., by war's end. During the entire war not more than a single vessel of the Auxiliary Patrol was captured by the Germans, though something like 400 vessels were lost - primarily trawlers employed in mine-sweeping activities.
The M.L. was deployed in flotillas of six craft throughout the various theaters of war - the English Channel and North Sea (primarily flotilla groups based in Dover, Harwich and Scapa Flow with numerous smaller ports having at least one M.L. flotilla), Ireland (Queenstown and Berehaven), and in French ports such as Dunkirk from which they patrolled along the northern coasts of France and Belgium. In the Mediterranean M.L. flotillas ranged from Gibraltar to the Adriatic and White Sea. Service ports included Taranto and Gallipoli (not the Gallipoli of the Dardanelles but the one in Italy), Otranto below Brindisi and Mudros, Lemnos and Imbros in the Greek islands. Further east M.L. flotillas could be found in Alexandria and Port Said, patrolling the Suez Canal, and toward the end of the war, in Beirut and Tripoli. There was even a flotilla on the West Indies station!