In case of loss of main and emergency electrical power, what term describes the source needed for GMDSS power?

The correct response is that the term used to describe the source needed for GMDSS (Global Maritime Distress and Safety System) power in case of loss of main and emergency electrical power is the reserve source of energy.

This terminology is essential because it highlights the critical need for a backup power system that ensures communication equipment remains operational during distress situations. The GMDSS system, which is designed for the safety of life at sea, requires a reliable source of electrical power to function effectively at all times. A reserve source of energy can include batteries or alternative power supplies that are specifically set aside for this purpose.

Using the term "reserve source of energy" accurately reflects the requirement for a reliable backup that can be accessed after the loss of primary power systems, ensuring that the ship can still send distress signals and maintain communication in emergencies, which is pivotal for mariner safety. Other options, while related, do not fully encompass the broader concept of having a dedicated backup system designed for emergency communication functions.