Operations designed to trap submarines required many destroyers. While those ships were searching, they could not escort convoys elsewhere. Keeping destroyers with merchant shipping offered a different way to bring escorts into contact with submarines when the latter tried to attack. A convoy that reached Britain without encountering a submarine had still achieved its purpose. Oracle moved to the Fourth Destroyer Flotilla for further convoy escort duties in October 1918, before hard service and hull deterioration ended her useful career.
Notable Point · 24:22-26:13
Why submarine sweeps competed with convoy protection
Large submarine sweeps absorbed destroyers that could otherwise protect merchant ships directly.