What is the requirement for emergency and reserve power in GMDSS radio installations?

In the context of GMDSS radio installations, the requirement for emergency and reserve power is critical to ensuring that a vessel can maintain communication capabilities during emergencies. Compulsory ships are mandated to have both emergency and reserve power sources specifically for radio communications. This requirement is in place to provide assurance that, in the event of a primary power failure, the vessel will still be capable of sending and receiving distress signals, which can be lifesaving.

The availability of emergency power ensures that the radio equipment remains operational under emergency conditions, while reserve power sources such as batteries provide additional support and a backup in the event of prolonged power loss. In essence, this combination is vital for maintaining continuous communication, which is essential for safety and emergency response.

Having only one power source, or relying solely on a backup EPIRB without the requisite radio communication systems in place, does not fulfill the regulatory requirements set by the GMDSS. Therefore, the correct answer emphasizes the necessity of both emergency and reserve power sources for effective communication during emergencies, aligning with international maritime safety standards.