Question 1

Your vessel receives a DSC (Digital Selective Calling) distress alert on 2187.5 kHz from another vessel, but no Coast Radio Station (CRS) acknowledgment is heard. What should you do, and why is a 5-minute wait significant?

Accepted Answer

Wait approximately 5 minutes for a CRS to acknowledge the distress alert, since a DSC distress alert is automatically repeated by the transmitting station at intervals of between 3.5 and 4.5 minutes if not acknowledged — if no acknowledgment is heard after this period and your vessel is able to assist, you should attempt to contact the nearest CRS by any available means and then communicate directly with the vessel in distress by radiotelephony (or NBDP) on the distress traffic frequency Under the GMDSS, a ship-to-shore DSC distress alert is automatically repeated by the originating station every 3.5 to 4.5 minutes until it is acknowledged (normally by a CRS). The roughly 5-minute waiting period allows time for that automatic acknowledgment to occur via the shore station, avoiding unnecessary duplicate transmissions and confusion on the distress frequency. If, after this period, no acknowledgment has been heard and your vessel is in a position to assist, you should attempt to raise the nearest CRS by any means available (including other radio bands) and then establish direct communication with the distressed vessel by radiotelephony on the appropriate distress traffic frequency (e.g. 2182 kHz for MF) to coordinate assistance. This question tests a Master's practical understanding of GMDSS distress procedures beyond simply knowing the equipment exists.

Question 2

You need to send a distress alert because the vessel is taking on water faster than the pumps can cope. Which message format and channel/priority is correct?

Accepted Answer

A "Mayday" distress call on Channel 16 / DSC distress alert, giving position, nature of distress and assistance required Grave and imminent danger requiring immediate assistance (e.g. uncontrolled flooding) requires a Mayday distress call / DSC distress alert — Pan-Pan is for urgency without immediate danger to life, and Securité is for navigational safety information.

Question 3

True or False: An EPIRB should be registered with the relevant national authority, and the registration details kept up to date so that a false alarm can be quickly resolved or a real activation correctly attributed.

Accepted Answer

True True. EPIRB registration links the unique beacon ID to vessel and contact details, allowing SAR authorities to quickly verify activations (genuine or false) and contact the vessel/owner — unregistered or out-of-date beacons slow down the SAR response and waste resources.