How often must a compulsory vessel's GMDSS radio station be inspected?

The correct answer is that a compulsory vessel's GMDSS radio station must be inspected annually, by the FCC or designated authority. This requirement is stipulated in regulations to ensure that vessels maintain their communication systems in effective working order, thereby enhancing safety at sea and compliance with international maritime standards.

Regular inspections are crucial for identifying potential issues with the radio equipment, ensuring it meets required operational standards and that all components function properly in emergency situations. This systematic approach to maintaining communication equipment is essential for the effectiveness of the GMDSS, which serves to facilitate search and rescue operations, broadcast maritime safety information, and ensure that vessels can communicate with each other and with shore authorities.

The context of the other choices includes varying responsibilities and time frames that are not aligned with the GMDSS regulations. The U.S. Coast Guard plays a significant role in maritime safety but does not impose the inspections directly; rather, they oversee compliance. While some vessels cruising outside designated areas may indeed require more frequent maintenance checks, the specific stipulation of six-month inspections isn't part of the standard annual inspection mandate. Additionally, while having monthly checks by an onboard GMDSS Radio Maintainer is good practice and beneficial, it does not substitute the formal inspection by the FCC or an authorized entity