For what purpose should distress signals be used?

Distress signals are specifically designed to indicate that a vessel, person, or craft is in peril and needs immediate assistance. The use of these signals is limited to situations where safety is at stake, making option D the correct choice. When distress signals are employed, they alert nearby vessels or rescue services to the fact that urgent help is required, thus eliciting a prompt response.

Using distress signals solely for emergencies emphasizes their critical role in maritime safety and ensures that they maintain their significance and urgency. This distinction is crucial because confusion could arise if these signals were used for non-emergency communications or practice, potentially leading to inadequate responses in real emergencies. By reserving distress signals exclusively for situations where help is needed, the maritime community can operate efficiently and effectively, aiding those in genuine distress without diluting the meaning of these important alerts.