Explanation: The master of the ship has ultimate control over all services aboard the vessel, including the radio station. This is a fundamental principle of maritime law and international radio regulations, such as those from the International Telecommunication Union (ITU) and the Safety of Life at Sea (SOLAS) convention. The master holds the overriding responsibility for the safety of the vessel, its crew, and passengers. While licensed radio operators are responsible for the proper technical operation and regulatory compliance of the radio equipment, their actions and the overall service of the radio station always fall under the master's command. No certificate, rank, or delegated authority can supersede the master's ultimate decision-making power regarding the ship's operations and safety.