Module 4 - Safety
Distress Communications
What you will learn
Select MAYDAY, PAN PAN or a safety message and lead the DSC-to-voice sequence without assuming one device guarantees contact or rescue.
The priority describes the real risk. MAYDAY is for grave and imminent danger requiring assistance; PAN PAN is an urgent concern about a person or vessel below that threshold.
For grave and imminent danger when assistance is required, send the VHF DSC distress alert on Channel 70 by pressing and holding the covered control until the set confirms it has sent. The alert identifies the vessel by MMSI and can include position and time when valid navigation data reaches the radio. It carries the selected nature of distress, or an undesignated distress if none was selected.
On receiving a DSC acknowledgement, or after about 15 seconds, transmit the voice MAYDAY call and message on Channel 16 when circumstances permit. Give MAYDAY three times, vessel name three times, call sign or other identity and MMSI, then repeat MAYDAY and state vessel identity, position, nature of distress, assistance required, people on board and other useful information before OVER.
PAN PAN is for an urgent concern about the safety of a person or vessel below the MAYDAY threshold. Current MCA small-boat guidance uses a DSC All Ships Urgency call with a nominated working channel, an announcement on Channel 16 and the full message on that working channel. Escalate to MAYDAY when the developing facts meet the distress threshold.
An EPIRB transmits a 406 MHz satellite distress alert; GNSS-equipped units can include position. A beacon carried on a UK-registered ship or watercraft must be registered with the UK Beacon Registry and kept current. A radar SART is a close-range locating aid. VHF range depends strongly on antenna height, so use complementary alerting and locating methods rather than treating any one device as a rescue guarantee.
Worked example
The yacht is taking water faster than the pumps can control it and the crew may have to abandon. A fixed VHF with valid position data and DSC is available.
- 1Press and hold the covered DSC distress control until the set confirms that the alert has been sent.
- 2On acknowledgement or after about 15 seconds, transmit the MAYDAY call and message on Channel 16.
- 3State the vessel identity, reliable position, uncontrollable flooding, assistance required, people on board and preparations being made.
- 4Maintain the listening watch, follow Coastguard directions and prepare appropriate locating and survival equipment without delaying immediate life-saving action.
Sense check: If the spoken message does not tell rescuers who, where, what is wrong, what help is needed and how many people are involved, it is not yet a useful MAYDAY message.
| Priority | Use it when | Initial route |
|---|---|---|
| MAYDAY | Grave and imminent danger; assistance required | DSC distress alert, then Channel 16 voice message |
| PAN PAN | Urgent safety concern below the MAYDAY threshold | DSC urgency announcement, Channel 16 call, then nominated working channel |
| Safety message | Navigational, weather or other safety information | Supported DSC safety procedure or Channel 16 call, then the directed channel |
Escalate from urgency to distress when the facts change
A yacht initially reports engine failure by PAN PAN while clear of danger. The wind strengthens and the yacht begins closing a lee shore faster than the anchor plan can arrest.
1. Reassess
Use distance, drift, sea room, anchor effectiveness and time to danger rather than the label used in the first call.
2. Escalate
If the situation is now grave and imminent and assistance is required, send the distress alert and MAYDAY message with the changed facts.
3. Update
Give a fresh position, people on board, current control measures and the assistance needed; maintain the listening watch.
Sense check: A previous PAN PAN does not prevent escalation. The signal must match the present risk and time available.
Common mistake or limitation
- A DSC alert does not contain every operational detail rescuers need; follow it with the voice message when possible.
- Position is included only when valid data reaches the radio, so the skipper must still be able to obtain and speak a reliable position.
- PAN PAN is not simply a quieter MAYDAY, and Channel 70 is never used for voice traffic.
Recap
- MAYDAY requires grave and imminent danger and a need for assistance; PAN PAN is an urgent safety concern below that threshold.
- Send the DSC distress alert, then speak the complete MAYDAY message on Channel 16 on acknowledgement or after about 15 seconds.
- Register and maintain 406 MHz beacons, and use complementary methods because range, valid position data and coverage vary.
Optional quick check
Section 2 of 10
A stable yacht has an injured crew member and needs urgent medical advice, but the stated facts do not show immediate danger to life. Which priority fits?
Continue studying Safety
This public lesson is part of Revision Module 4. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.