The Royal Observer Corps operated an extensive network of underground monitoring posts in the United Kingdom. During the Cold War, more than 1,500 small sites and the Group Headquarters associated with them were intended to detect nuclear detonations and track radioactive fallout. ROC26 aims to commemorate the history of the people who operated this infrastructure.
During the event, radio amateurs will activate sites included on the official ROC26 list. The station must operate within a maximum radius of 1,000 metres of the specified bunker location, and at least 25 QSO points are required for a valid activation. All bands and modes permitted by the operator's licence are allowed; however, the rules exclude counting contacts made via repeaters and Internet gateways.
In 2026, the organiser introduced additional points for activating particularly important sites from the former network. Master Post is worth a three-point bonus, while Group HQ – five points. The system covers 25 former Royal Observer Corps organisational areas. A separate classification has also been prepared for chasers and SWLs.
UKBOTA also reminds participants that listing a site in the database does not automatically grant access or guarantee safety. Operators should carry out their own risk assessment and, when operating on private property, obtain the owner's permission.