CIMSEC – The historic success of the Coastwatchers provides valuable insight for naval intelligence in the future single naval battle. Proactive intelligence, multi-domain intelligence, and local access and support remain necessary for an effective naval intelligence operation. Naval forces will grow stronger through these lessons as the world’s security environment becomes more complex and dynamic. The future challenge is to harmonize these lessons into a single integrated naval force. As the naval force tackles this and other challenges, remember the Coastwatchers.