How is normal working conditions restored on a SITOR (NBDP) frequency after radio silence?

The restoration of normal working conditions on a SITOR (NBDP) frequency after a period of radio silence is specifically managed by a designated authority. In this context, the High Seas Service plays a critical role in maintaining maritime safety and communication protocols. When radio silence is imposed, it is essential for the High Seas Service to formally notify all stations that normal operations can resume. By transmitting the message "SILENCE FINI", they ensure that all parties are clear that the previously imposed silence has been lifted, thereby allowing for the resumption of regular communications.

This procedure is in place to prevent any confusion that might arise from multiple stations trying to communicate at the same time after a silence period, which could potentially impede safety-related messages or routine traffic. The clear authority and structured communication process help maintain order in maritime communications, ensuring that all operators are operating with the same understanding regarding the status of the frequency.