Ian Waugh - A Mariner\'s Guide to Marine Communications

'GWIZ this isJustinalGJUS - two miles West of Dunderhead Buoy - I have d eep

draft and must remain in th e ce ntre of the channel until seaward

of Dunderhead Buoy, then steering course HiS degrees into Bent Strait -

please keep clear of channel entrance until I am clear - Over'

'justina this is GWIZ - received - I will hold my present position until you arc

clear and on course for Bent Strait

Dangers in the use of VHF radio in collision avoidance

Numerous notices have been published by the IMO and others

regarding the use of VHF in collision avoidance. The main point to

remember is stated as "Although the use of VHF radio may be justified

on occasion in collision avoidance, the provisions of the Collision

Regulations should remain uppermost, as misunderstandings can arise

even where the language of communication is not a problem"

Automatic Identification Systems (AIS)

The latest version of marine VHF DSC Radio includes AIS
channels to interrogate other vessels in the vicinity and generate a DSC
response showing the other vessel's identity (MMSI), position, course
and speed. AIS systems will become compulsory on SOLAS vessels
between 1 July 2002 and 1 July 2007. AIS systems will allow you to
identify an approaching vessel - so you can call them by DSC, or by
voice on Ch 13, using their individual MMSI.

Questions from Chapter 5
1 What initial action should you take on receiving a DSC Distress Alert
on Ch70?
2 What would normally be the first choice DSC Distress Alerting
frequency when in an A2 area (Ch70, 2177kHz, 2187.5kHz or
8414.5kHz)?
3 Write down an EXAMPLE of a voice Distress Call and Message on
Ch1612182kHz.
4 Give an example of an initial voice acknowledgement of a Distress
Message.
S Who should you inform/consult before sending a DSC Distress
Acknowledgement?
6 Who is responsible for committing your vessel to attend a distress
incident?
7 What action should you take if you send a False Distress Alert on
Ch70?
8 On what frequencies should a SOLAS vessel maintain watch, in an
A3/A4 area (assuming DSC for all areas)?
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