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Reception of an urgency message






Ships receiving a DSC urgency call announcing an urgency message addressed to all ships shall NOT acknowledge the receipt of the DSC call, but should tune the radiotelephony receiver to the frequency indicated in the call and listen to the urgency message.

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Safety

Transmission of safety messages

Transmission of safety messages shall be carried out in two steps:

o announcement of the safety message,

o transmission of the safety message.

The announcement is carried out by transmission of a DSC safety call on the DSC distress calling channel (2187.5 kHz on MF, channel 70 on VHF).

The safety message is normally transmitted on the distress and safety traffic channel in the same band in which the DSC call was sent, i.e. 2182 kHz on MF, channel 16 on VHF.

The DSC safety call may be addressed to all ships, all ships in a specific geographical area or to a specific station.

The frequency on which the safety message will be transmitted shall be included in the DSC call.

The transmission of a safety message is thus carried out as follows: Announcement:

39. tune the transmitter to the DSC distress calling channel (2187.5 kHz on MF, channel 70 on VHF);

40. select the appropriate calling format on the DSC equipment (all. ships, area call or individual call);

41. key in or select on the DSC equipment keyboard:

§ specific area or 9-digit identity of specific station, if appropriate,

§ the category of the call (safety),

§ the frequency or channel on which the safety message will be transmitted,

§ the type of communication in which the safety message will be given (e.g. radiotelephony),

in accordance with the DSC equipment manufacturer's instructions;

42. transmit the DSC safety call.

Transmission of the safety message:

43. tune the transmitter to the frequency or channel indicated in the DSC safety call;

44. transmit the safety message as follows:

§ " SECURITE", repeated 3 times,

§ " ALL STATIONS" or called station, repeated 3 times,

§ " this is",

§ the 9-digit identity and the call sign or other identification of own ship,

§ the text of the safety message.

Reception of a safety message

Ships receiving a DSC safety call announcing a safety message addressed to all ships shall NOT acknowledge the receipt of the DSC safety call, but should tune the radiotelephony receiver to the frequency indicated in the call and listen to the safety message.

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Public correspondence

DSC channels for public correspondence

VHF

The VHF DSC channel 70 is used for DSC for distress and safety purposes as well as for DSC for public correspondence.

MF

International and national DSC channels separate from the DSC distress and safety calling channel 2187.5 kHz are used for digital selective-calling on MF for public correspondence.

Ships calling a coast station by DSC on MF for public correspondence should preferably use the coast station's national DSC channel.

The international DSC channel for public correspondence may as a general rule be used between ships and coast stations of different nationality. The ships transmitting frequency is 2189.5 kHz, and the receiving frequency is 2177 kHz.

The frequency 2177 kHz is also used for digital selective-calling between ships for general communication.


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