US Navy stationing large number of submarine chasers in European waters during First World War

Preliminary design no. 186 for an American submarine chaser dated 22-11-1917

An item reported that in the First World War the US Navy stationed 120 submarine chasers in the Irish Sea, British Channel and the Adriatic Sea to support the Allies against enemy submarine activities. For that purpose were 5 special and 3 auxiliary bases established. The submarine chasers operated in groups with crews trained in using listening devices to track submarines. There wre numerous contacts made and attacks executed.  

Source

Information concerning the U.S. Navy and other navies. Office of Naval Intelligence July, 1919