Which distress term is used to indicate grave danger and requires immediate assistance via radio?

• A. Mayday
• B. SOS
• C. Pan-Pan
• D. Securite

Answer: (A)

Grave danger requiring immediate help is conveyed with the Mayday signal. On radiotelephony, you start by saying Mayday three times to clear the path and confirm it's a real distress call, then identify your vessel, position, the nature of the distress, how many people are aboard, and the type of assistance needed. The threefold repetition helps ensure the message is heard and understood in noisy conditions and across different stations.

SOS is an older Morse-code distress signal, not typically spoken over a voice radio. Pan-Pan signals an urgent situation but not one of imminent danger to life. Securite is used for safety information and navigational warnings, not for distress. So Mayday is the appropriate term for grave danger requiring immediate assistance.