NAVTEX and EGC Reception in a Coastal Passage
You are the navigating officer on a 120 m general cargo ship on passage along a coast where NAVTEX coverage is provided by two stations, one transmitting on 518 kHz and one on 490 kHz. The vessel's NAVTEX receiver is a dual-frequency model set to receive 518 kHz and 490 kHz. The receiver display shows '518: no messages' and '490: no messages' for the last 12 hours, although the vessel is within 60 nm of the coast. The master asks whether the MSI requirement is being met and whether the EGC/SafetyNET terminal should be used instead. The vessel is in sea area A2 and has an Inmarsat-C terminal with EGC capability. The NAVTEX antenna is mounted on the monkey island near the radar mast.
1. Explain the likely reasons for the absence of NAVTEX messages and what checks you would make.
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Absence of messages does not necessarily mean no MSI is being broadcast; it can mean the receiver is not receiving, is tuned to the wrong frequency, or the station is not transmitting at that time. Check that the receiver is actually tuned to 518 kHz (international) and 490 kHz (national) and that the correct station is selected. Check the antenna and feeder for damage, corrosion or water ingress, and confirm the antenna is not screened by the radar mast or other structures. Check the receiver's message-type settings: if all message types are deselected, no messages will be displayed. Confirm the receiver's clock and that the station's transmission schedule is being observed. Also check the power supply and that the receiver is not in a 'test' or 'standby' mode. If the receiver is functioning, try a different frequency or station, and cross-check with EGC/SafetyNET.
2. Describe how EGC/SafetyNET can be used to meet the MSI requirement and what limitations apply.
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In sea area A2, NAVTEX is the primary MSI receiver, but EGC/SafetyNET via Inmarsat-C can provide MSI as a supplementary or alternative means, particularly where NAVTEX coverage is unreliable. The Inmarsat-C terminal must be logged on and configured to receive EGC messages for the appropriate ocean region and area. EGC messages are broadcast by SafetyNET providers and can include navigational warnings, meteorological warnings, search and rescue information and other urgent information. Limitations include: the terminal must be operational and logged on; EGC reception depends on satellite coverage and antenna; the service may not carry all the same message types as NAVTEX; and the vessel must still comply with the carriage requirement for the appropriate MSI receiver for its sea area. The EGC terminal should be tested and the message log checked regularly.
3. What records and actions should be taken if MSI is not being received?
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Record the failure in the radio log, including the time, the receiver status, the checks made and the action taken. Inform the master. If the NAVTEX receiver is faulty, arrange repair or use the EGC/SafetyNET terminal as an alternative and record that use. If neither is available, the vessel should consider obtaining MSI by other means, such as broadcast radio or contacting an RCC, and should note the deficiency. The deficiency should be reported to the flag state or recognized organization as required, and the MSI receiver should be restored to full operation before the next voyage.