Problem 1: Wrongful DSC Distress Acknowledgement
When a DSC Distress Alert is received onboard another vessel, alarms
sound - on some makes of equipment these alarms are very loud.
Some equipment also offers the Bridge Watchkeeper an 'ACK' (DSC
Distress Acknowledgement) facility, at the push of a button, as soon
as a DSC Distress Alert is received. Some Bridge Watchkeepers are
using this 'ACK' button to silence the alarms on their equipment -
without realising that they are transmitting a DSC Distress
Acknow ledgement.Answer: Ships receiving a DSC Distress Alert should not
'ACKnowledge' the alert by DSC without first consulting a Coast
Station/MRCC (IMO COMSARlCirc.21 refers).
Problem 2 : Wrongful DSC Distress Relay
Other Bridge Watchkeepers, being unsure of the correct action to take,
are pressing the 'RELAY' button - possibly assuming that they are
helping the situation by passing-on the problem to someone else; they
are making it worse:
Answer: Ships should not transmit a DSC Distress Relay call on first
receipt of a DSC Distress Alert. They should not transmit a DSC
Distress Relay unless they have gone through the correct listening
procedure on the associated voice/telex channel indicated in the
Distress Alert. DSC Distress Relays should normally be sent direct to
an individual Coast Station/MRCC (using the individual MMSI of
the Coast Station/MRCC - obtainable from ALRS Volume 5) - and
not to 'ALL STATIONS'Distress Relay (Radio Procedures)
A DSC Distress Relay, followed by a voice Mayday Relay call
and message, is normally transmitted by a Coast Station/MRCC when
it is necessary to attract the attention of other vessels in the vicinity of
the casualty. The Coast Station/MRCC may also send a DSC Distress
Relay/voice Mayday Relay call and message, at regular intervals, to
provide a summary of the situation to all vessels in the area.
A ship can, on the authority of the master, send a DSC Distress
Relay/voice Mayday Relay call and message, when:
(i) You have seen/heard distress signals that have not been acknowledged;
OR
(ii) A vessel in distress is unable to send its own distress message; AND
additional help is required to effect rescue.
MARINE COMMUNICATIONS 97