From 1925 to 1927 Somerville headed Royal Navy signals at a moment when wireless practice was becoming central to fleet tactics. The position let him write Signal School curricula, set fleet standards, and advise the Sea Lords from a depth of technical knowledge they could not easily challenge. Night fighting made the problem acute because flags could not be seen and signal lamps could reveal a ship's position. Radio solved the visibility problem but created interception and direction-finding risks of its own. His office therefore sought to convey maximum information in the shortest possible transmission while protecting both a force's location and its operational intent.
Chapter · 54:10-57:16
Designing interwar signals for night fighting
As Director of Signals, Somerville shaped the standards, training, and low-signature radio methods needed for the Royal Navy's interwar night-fighting doctrine.