Which commercial radio operator license is required to operate a fixed-tuned ship RADAR station with external controls?

To understand why the answer "No radio operator authorization is required" is correct, it's important to consider the specific functions and regulations surrounding ship RADAR stations. Ship RADAR systems that are fixed-tuned and operated with external controls do not fall under the category of equipment that necessitates a radio operator authorization.

The regulations typically state that commercial radio operator licenses are required for devices that transmit radio frequency signals. However, fixed-tuned ship RADAR systems primarily serve navigational purposes and do not transmit information; rather, they receive and display information related to the surroundings of the vessel. Hence, operating such a system does not demand the same level of regulatory oversight or certification that is mandatory for other radio communications.

While other licenses mentioned—such as a radio operator certificate with a Ship RADAR Endorsement, a Marine Radio Operator Permit, or higher levels of radiotelegraph certificates—are necessary for other types of communication devices that transmit and require monitoring, they do not apply in this scenario. Therefore, operating a fixed-tuned ship RADAR station does not require prior authorization or specialized training as long as the system is used appropriately within the confines of its specifications and limitations.