Mayday relay with an incomplete DSC position
At 0342 local time you are the GOC holder on a 4,500 GT cargo ship 12 nm off the Nigerian coast, inbound to Lagos. The VHF DSC controller alarms: a distress alert from MMSI 657003421, nature 'undesignated', no position. On Ch16 a weak voice repeats: 'Mayday, mayday, this is fishing vessel Saint Mary, we are taking water, three persons on board, no liferaft.' The transmission is broken and the position is partly masked by noise. Lagos Radio/MRCC has not acknowledged after four minutes. Your vessel is making 9 knots and is about 7 nm from the position you think you copied; sea state 3, visibility good. You carry a fast rescue boat but no helicopter. The master asks whether you should acknowledge, relay, and alter course. Another merchant vessel is 15 nm away and has also acknowledged hearing the MAYDAY on Ch16.
1. State whether you should send a DSC acknowledgement, a MAYDAY RELAY, or both. Give the exact priority and content of your first radiotelephony transmission and the reasoning behind the order.
Read the worked answer
No DSC acknowledgement. A DSC distress alert is normally acknowledged by a coast station or RCC; a ship should not send a DSC acknowledgement because multiple acknowledgements can clutter the distress traffic and confuse the SAR co-ordinator. However, after about four to five minutes with no coast-station acknowledgement, and since you are able to assist, you may acknowledge by radiotelephony on Ch16. First establish contact: 'MAYDAY Saint Mary, MAYDAY Saint Mary, this is [your ship name, call sign, MMSI], received MAYDAY, over.' Keep it short. Then send a distress relay to the coast station/all stations: 'MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY, all stations, this is [name/call sign/MMSI], received MAYDAY from Saint Mary, MMSI 657003421, position [as copied], nature taking water, three persons on board, no liferaft, assistance required, over.' The relay is justified because the original alert had no position and no coast-station acknowledgement; it alerts MRCC and other ships without waiting. Do not press your own DSC distress button. If MRCC then acknowledges, leave distress traffic to it and follow instructions.
2. What information must you obtain from Saint Mary, and what will you pass to MRCC? How should you coordinate with the other merchant vessel?
Read the worked answer
Obtain: confirmed position (latitude/longitude or bearing and distance from a known point), number of persons, injuries, life-saving appliances, whether they have a working VHF/EPIRB, rate of flooding and pumps, and whether they can see your vessel. Pass to MRCC: your identity and MMSI, time you received the alert, the fishing vessel's MMSI and name, the position you copied and its uncertainty, nature of distress, POB, on-scene weather, your distance/speed/ETA, rescue boat capability, and the other merchant vessel's presence. Use Ch16 for control and move to a working channel when MRCC directs. For coordination, avoid two ships transmitting at once; if MRCC is in control, let it assign roles. If no MRCC, the closest capable vessel should take the lead and the other should stand by as backup; keep a listening watch and do not leave the scene until released.
3. If voice contact is lost and the fishing vessel cannot be seen, should you continue to the reported position? What precautions and records are required?
Read the worked answer
Yes, proceed toward the reported position unless doing so would endanger your own ship; the obligation to assist persons in distress is strong, and a fast rescue boat is useful only if you are on scene. Inform MRCC of your course and ETA, post extra lookouts, use radar and searchlights, and prepare the rescue boat and recovery equipment. If you cannot see the vessel, do not simply anchor; start a systematic search using the last known position and drift, and ask MRCC for a search pattern. Record in the radio log and official logbook: times of alert, transmissions, positions, courses, weather, and decisions. Preserve any recordings. If another vessel is closer, coordinate so that one vessel searches and the other stands by; continue until MRCC releases you.