Why Pound preferred convoy protection to Scheme Z

Admiral Pound's dispatch of 8 September 1937 criticizes Scheme Z for lacking the convoy system's immediate counterattack advantage. An attack on an escorted convoy takes place in the presence of the force that can respond, while dispersed hunters first have to find the submarine. Pound considers continuous air patrols essential for locating submarines during daylight and proposes using Glorious or another carrier until flying boats arrive. Concentrated destroyer searches compete with the need to disperse ships widely enough to reach an attack quickly. Three-destroyer units offer a compromise. At night, submarines could leave Spanish ports, attack, and return without the same aerial observation.