What would be an indication of a malfunction on a GMDSS station with a 24 VDC battery system?

Correct Answer: Option A — A constant 30 volt reading on the GMDSS console voltmeter.

A constant 30-volt reading on a 24-volt system indicates a failure in the charging regulator or a shorted cell, as the voltage should typically float between 24 and 27 volts. Sustained overvoltage can damage sensitive GMDSS radio components and indicates an urgent need for maintenance to prevent equipment failure.