DSC Procedures VHF, MF, and HF
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Transcript DSC Procedures VHF, MF, and HF
DSC PROCEDURES FOR
VHF AND MF
Transmission of DSC distress alert
A distress alert should be transmitted if, in the opinion
of the Master, the ship requires immediate assistance.
A DSC distress alert should include the ship’s last
known position and time in UTC.
The DSC alert is transmitted as follows:
Tune the transmitter to the DSC distress channel (MF-
2187.5 kHz, VHF channel 70)
If time permits, select the nature of distress
The ship’s last known position
Time in UTC
Type of subsequent distress communication
Transmit the DSC distress alert
Prepare for the subsequent distress traffic by tuning the
radiotelephony transmitter to the distress traffic channel in
the same band. (2182 kHz on MF,
channel 16 on VHF while waiting for
the distress acknowledgement.
Actions on receipt of a distress alert
Wait for the coast station to acknowledge first.
If the alert is still continuing, acknowledge the distress
alert and inform Coast Station or RCC
Tune the radiotelephony receiver to the distress traffic in
the same band.
Transmission of a DSC distress relay
Tune the transmitter to the DSC distress channel (MF-
2187.5 kHz, VHF channel 70)
Select the distress relay call format
Key in - All ships call (VHF); Geographic Area Call
(MF/HF); or Coast Stations MMSI.
Station in distress MMSI, if known.
The nature of distress, position and time if known.
Type of distress communication
Transmit the DSC distress relay call
Prepare for the distress traffic while waiting for the
acknowledgement.
Cancellation of an inadvertent distress alert
A station transmitting an inadvertent distress alert shall
cancel the distress alert:
Immediately cancel the distress alert aurally over the
associated telephony distress channel
Monitor the associated telephony distress traffic channel
and respond to any communications concerning that
distress alert as appropriate.
All stations All stations All stations
This is
BRUNITA, BRUNITA, BRUNITA CALLSIGN LKFE,
MMSI 257666000
In position 14°34’ N 120° 23E
Please cancel my distress alert of 23 Feb, 0400H UTC
Date and Time 23 of Feb., 0500H UTC
Master MV BRUNITA Callsign LKFE
Transmission of urgency messages
The broadcast of an urgency message is carried out on a DSC
urgency call:
Tune the transmitter to the DSC distress channel (MF2187.5 kHz, VHF channel 70)
Key in - All ships call (VHF) or Geographic Area Call
(MF/HF) or individual call
The category of call (urgency)
Working frequency or channel
Type of communication
Transmit the
DSC urgency call
Transmission of safety messages
The broadcast of a safety message is carried out on a DSC
safety call:
Tune the transmitter to the DSC distress channel (MF2187.5 kHz, VHF channel 70)
Key in - All ships call (VHF) or Geographic Area Call
(MF/HF) or individual call
The category of call (safety)
Working frequency or channel
Type of communication
Transmit the
DSC safety call
Public Correspondence
The Public correspondence is carried out on a DSC routine
call:
Tune the transmitter to the DSC distress channel (MF2187.5 kHz, VHF channel 70 or the coast station’s working
frequency)
Key in the MMSI of a particular station to be called
The category of call (routine)
Working frequency or channel
Type of communication
DISTRESS
Transmit the
URGENCY
DSC routine call
SAFETY
IMPORTANT SHIP TRAFFIC
ROUTINE
Repeating a DSC Call
DSC Call for public correspondence may be repeated on
the same or another DSC channel/frequency, if no
acknowledgement is received within 5 min.
Further call attempts should be delayed at least 15 min, if
acknowledgement is still not received.
DSC Test call
DSC PROCEDURES FOR
HF
Transmission of DSC distress alert
DSC distress alert should be sent to coast stations A3 and
A4 sea areas on HF.
Propagation characteristics of HF radio waves should be
taken into account in choosing HF bands for transmission
of DSC distress alert.
8414.5 kHz may in many cases be an appropriate first
choice.
Transmission of the DSC distress alert in more than one
HF band will normally increase the probability of
successful transmission..
The HF DSC distress alert
Tune the transmitter to the HF DSC distress frequency
(4207.5, 6312, 8414.5, 12577, 0r 16804.5 kHz)
If time permits, select the nature of distress
The ship’s last known position
Time in UTC
Type of subsequent distress communication
Transmit the DSC distress alert
Prepare for the subsequent distress traffic by tuning the
radiotelephony transmitter to the appropriate distress
traffic frequency in the same band while waiting for the
distress acknowledgement.
HF Distress and Safety calling
Frequencies
DSC (kHz)
4297.5
6312.0
8414.5
12577.0
16804.5
Telephony (kHz)
4125
6215
8291
12290
16420
Radiotelex (kHz)
4177.5
6268.0
8376.5
12520.0
16695.0