Under GMDSS, the Reserve Source of Energy must be independent of the ship's electrical system when powering which equipment?

• A. Non-GMDSS communications equipment
• B. GMDSS equipment
• C. Navigation sensors
• D. Crew entertainment devices

Answer: (B)

The main idea is that life-saving communications must stay available even if the ship loses its main power. To ensure this, the Reserve Source of Energy is dedicated to powering the GMDSS equipment and is independent from the ship’s normal electrical system. That independence means the GMDSS gear—used for distress alerts and safety communications—can operate on its own power if the main generators or power distribution fail, for the required period. Other equipment like non-GMDSS communications, navigation sensors, or crew entertainment does not have the same mandatory safeguard, so they don’t require this independent reserve power.