What action should mariners take when they observe another vessel using distress signals?

When mariners observe another vessel using distress signals, it is crucial to report the situation to authorities immediately. Distress signals are a clear indication that a vessel is in trouble and requires assistance. Reporting the situation allows trained professionals or nearby vessels to respond effectively, ensuring the safety of those in distress. This action aligns with maritime safety protocols designed to prioritize life-saving efforts and facilitate a prompt rescue operation.

Other responses might involve further actions, but they do not adequately prioritize the immediate need for reporting. For example, ignoring the signals unless in close proximity could lead to delays in response, potentially putting lives at risk. Responding only in an emergency situation fails to recognize that the distress signal itself indicates an emergency. Asking the vessel if they need assistance may not be practical or possible if the vessel is unable to communicate effectively. Thus, reporting to authorities stands out as the most responsible and critical action to take.