Which of the following statements about power sources in GMDSS-equipped ships is correct?

• A. Both emergency and reserved power sources must be provided.
• B. Only a main power source is required.
• C. Power sources are not required on small vessels.
• D. Backup power is optional.

Answer: (A)

Redundancy in power sources is required for GMDSS equipment. Ships equipped with GMDSS must have more than one independent power source so essential communications and safety systems can keep operating even if the main power fails. This means there is a primary power source plus emergency and reserve (backup) power supplies dedicated to powering the GMDSS and life-saving equipment. The emergency power source ensures critical gear can run for the required duration during a power outage, while the reserve power provides an additional independent source to maintain operation if the emergency source is unavailable. Without both emergency and reserve power, a single failure could leave distress and safety communications unusable, which is why that option is correct.