Auxiliary Patrol Zones

The following description of the Auxiliary Patrol areas of operation and parent ships is taken from British Warships 1914-1919 by Dittmar and Colledge. A highly recommended resource giving good detail regarding ML deployments during the war.

The descriptions should be read in conjunction with the two maps provided by Dittmar and Colledge: Home Waters Patrol Areas and Mediterranean Sea Patrol Zones.

Sufficient numbers of patrol vessels were available by December 1914 to provide coastal patrols of moderate strength surrounding the home Islands. Areas received numeral designations which were first listed 19.12.14. These designated areas remained effective until the 1919 demobilisation period. The summer of 1915 saw the patrol organisation approaching maturity, by this time basically similar to the charts indicating area status and strength for January 1917. Alterations after January 1917 included combining areas II and Ill, combining areas VI and VII, the addition of new area Xllla (Devonport) from 1.4.17 created from within areas XIII and XIV. Original area XIX (Killybegs) became new area XlXa with altered boundaries in May 1918. Area XX (Galway Bay) was reduced in size and re-numbered to become new area XIX; the remaining southernmost portion made up new area XX (Berehaven). The limits of each area necessarily more cleariy defined as the organisation grew and operations extended farther from land. Assignment of vessels and armed patrols within each area was dictated by the war threat to which it was exposed and as the operational range of enemy submarines was increased, realignment of defensive measures became necessary. Extension of the patrol activities into the Mediterranean began when trawler-minesweePerS were used in the first attempts to force the Dardanelles. Later they were used to establish a firmer grip on the entire Mediterranean area, thusiy making new demands on the ships and men of the fishing fleet. Another notable concentration of smalicraft developed when net drifters were attached to the Taranto (Italian) zone.

The Mediterranean Sea was divided into patrol zones dividing responsibility between the British, French and Italian navies. The charts dated 3.1.17 best illustrate the final number and extent of operational areas at the height of the sea war. Numbers In the patrol service are given for the first Red list issued in January of each year from 1915 to 1919. Since totals were under constant revision all during this period these figures represent the minimal strength of the Patrol; even the official sources differed slightly with regards to the precise numbers and some of the less prominent types were occasionally overlooked. In the following list of areas and zones which is keyed to the two charts for 3.1.11, parent ships are also given. Since command of several areas were sometimes under the same admiral, there are fewer parent ships than patrol areas. The limits of each area were normally taken from lines extended from light houses buoys or prominent land features, all of which were easily seen. Naturally the coastline served as the inner limits, but the outer extremes were defined as "as far as necessary".