A complete inventory of all COMSEC material held by a watch station must be conducted whenever what occurs?

A complete inventory of all COMSEC material held by a watch station must be conducted whenever watch personnel change because this ensures that the new personnel have an accurate understanding of what COMSEC materials are available and that they are responsible for securing that information. Changing personnel can introduce risks if there is not a comprehensive inventory check, as it helps to confirm that no materials are missing and that all items are accounted for. This process underlines the significance of maintaining control over sensitive materials, as new personnel must be briefed on their responsibilities and the security protocols involved in handling COMSEC material. This step is crucial for maintaining the chain of custody and ensuring that the integrity of secure communications is upheld at all times. Other scenarios, such as scheduling monthly reviews, initiating training sessions, or revising access requirements, do not necessitate an immediate inventory update in the same way that a personnel change does.