REVOKES A.474(XII).
THE ASSEMBLY,
RECALLING Article 15(j) of the Convention on the International Maritime Organization concerning the functions of the Assembly in relation to regulations and guidelines concerning maritime safety,
RECOGNIZING that proper use of VHF radiocommunication channels contributes to safety of life at sea and efficiency of navigation,
RECOGNIZING ALSO that misuse of VHF radiocommunication channels may cause serious interference with essential communications and might cause potential dangers to safety at sea,
CONSIDERING that the risk of misuse of VHF radiocommunication channels is more likely when VHF equipment is operated by persons not trained in its proper use,
RECALLING that the Radio Regulations* require that the service of every ship radio-telephone station should be controlled by an operator holding a certificate issued or recognized by the Government concerned,
RECALLING ALSO that, for the certification of masters, chief mates and officers in charge of a navigational watch, the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, 1978, as amended in 1995, requires knowledge of procedures used in radiotelephone communications and the ability to use radiotelephones, in particular with respect to distress, urgency, safety and navigational messages,
HAVING CONSIDERED the recommendation made by the Maritime Safety Committee at its seventy-fifth session,
1. ADOPTS the Guidelines on the use of VHF at sea as set out in the annex to the present resolution;
2. INVITES Governments to ensure that all persons on board controlling the operation of VHF equipment have knowledge of the procedures used in radiotelephone communications and the ability to use radiotelephones, in particular with respect to distress, urgency, safety and navigational messages;
3. INVITES ALSO Governments to bring the annexed Guidelines to the attention of all concerned;
4. INVITES FURTHER Governments to take appropriate action to ensure that VHF channels are used correctly;
5. AUTHORIZES the Maritime Safety Committee to keep these Guidelines under review and amend them as appropriate;
6. REVOKES resolution A.474 (XII).
* Radio Regulations means the Radio Regulations annexed to, or regarded as being annexed to, the most recent International Telecommunications Convention which is in force at any time.
01 VHF Communication technique
01.01 Preparation
Before transmitting, think about the subjects which have to be communicated and, if necessary,
prepare written notes to avoid unnecessary interruptions and ensure that no valuable time is
wasted on a busy channel.
01.02 Listening
Listen before commencing to transmit to make certain that the channel is not already in use. This
will avoid unnecessary and irritating interference.
01.03 Discipline
VHF equipment should be used correctly and in accordance with the Radio Regulations. The
following in particular should be avoided:
.1 calling on channel 16 for purposes other than distress, urgency and very brief
safety communications when another channel is available;
.2 communications not related to safety and navigation on port operation channels;
.3 non-essential transmissions, e.g. needless and superfluous signals and
correspondence;
.4 transmitting without correct identification;
.5 occupation of one particular channel under poor conditions; and
.6 use of offensive language.
01.04 Repetition
Repetition of words and phrases should be avoided unless specifically requested by the receiving
station.
01.05 Power reduction
When possible, the lowest transmitter power necessary for satisfactory communication should be
used.
01.06 Automatic Identification System (AIS)
AIS is used for the exchange of data in ship-to-ship communications and also in communication
with shore-based facilities. The purpose of AIS is to help identify vessels; assist in target
tracking; simplify information exchange (e.g. reduce verbal reporting); and provide additional
information to assist situation awareness. AIS may be used together with VHF voice
communications. AIS should be operated in accordance with resolution A.917(22), as amended
by resolution A.956(23) on Guidelines for the onboard operational use of shipborne automatic
identification systems (AISs).
01.07 Communications with coast stations
1.7.1 On VHF channels allocated to port operations service, the only messages permitted are
restricted to those relating to the operational handling, the movement and the safety of ships and,
in emergency, to the safety of persons; as the use of these channels for ship-to-ship
communications may cause serious interference to communications related to the movement an
safety of shipping in port areas.
1.7.2 Instructions given on communication matters by shore stations should be obeyed.
1.7.3 Communications should be carried out on the channel indicated by the coast station.
When a change of channel is requested, this should be acknowledged by the ship.
1.7.4 On receiving instructions from a coast station to stop transmitting, no further
communication should be made until otherwise notified (the coast station may be receiving
distress or safety messages and any other transmissions could cause interference).
01.08 Communications with other ships
1.8.1 VHF channel 13 is designated by the Radio Regulations for bridge-to-bridge
communications. The ship called may indicate another working channel on which further
transmissions should take place. The calling ship should acknowledge acceptance before
changing channels.
1.8.2 The listening procedure outlined in paragraph 1.2 should be followed before
communications are commenced on the chosen channel.
01.09 Distress communications
1.9.1 Distress calls/messages have absolute priority over all other communications. When
receiving them all other transmissions should cease and a listening watch should be kept.
1.9.2 Any distress call/message should be recorded in the ship's log and passed to the master.
1.9.3 On receipt of a distress message, if in the vicinity, immediately acknowledge receipt. If
not in the vicinity, allow a short interval of time to elapse before acknowledging receipt of the
message in order to permit ships nearer to the distress to do so.
01.10 Calling
1.10.1 In accordance with the Radio Regulations channel 16 may only be used for distress,
urgency and very brief safety communications and for calling to establish other communications
which should then be conducted on a suitable working channel.
1.10.2 Whenever possible, a working frequency should be used for calling.
If a working frequency is not available, VHF channel 16 may be used for calling, provided it is
not occupied by a distress and urgency call/message.
1.10.3 In case of a difficulty in establishing contact with a ship or a coast station, allow adequate
time before repeating the call. Do not occupy the channel unnecessarily and try another channel.
01.11 Changing channels
If communications on a channel are unsatisfactory, indicate change of channel and await
confirmation.
01.12 Spelling
If spelling becomes necessary (e.g. descriptive names, call signs, words that could be
misunderstood) use the spelling table contained in the International Code of Signals, the Radio
Regulations and the IMO Standard Marine Communication Phrases (SMCP).
01.13 Adressing
The words "I" and "YOU" should be used prudently. Indicate to whom they refer.
Example:
"Seaship, this is Port Radar, Port Radar, do you have a pilot?
Port Radar, this is Seaship, I do have a pilot."
01.14 Watchkeeping
Every ship, while at sea, is required to maintain watches (Regulation on Watches in Chapter IV
of SOLAS, 1974, as amended). Continuous watchkeeping is required on VHF DSC channel 70
and also when practicable, a continuous listening watch on VHF channel 16.
02 VHF Communication procedures
02.01 Calling
When calling a coast station or another ship, say the name of that coast station once (twice if
considered necessary in heavy radio traffic conditions) followed by the phrase THIS IS and the
ship's name twice, indicating the channel in use.
Example:
"Port City, this is Seastar, Seastar, on Channel 14."
02.02 Exchange of messages
2.2.1 When communicating with a ship whose name is unknown but whose position is known,
that position may be used. In this case the call is addressed to all ships.
Example:
"Hello all ships, this is Pastoria, Pastoria. Ship approaching number four buoy, I am
passing Belinda Bank Light."
2.2.2 Where a message is received and only acknowledgement of receipt is needed, say
"received". Where a message is received and acknowledgement of the correct message is
required, say "received, understood", and repeat message if considered necessary.
Example:
"Message: Your berth will be clear at 08.30 hours.
Reply: Received, understood. Berth clear at 08.30 hours."
2.2.3 Where appropriate, the following message should be sent:
"Please use/ I will use the IMO Standard Marine Communication Phrases".
When language difficulties exist which cannot be resolved by use of the IMO Standard Marine
Communication Phrases , the International Code of Signals should be used.
In this case, the word "INTERCO" should precede the groups of the International Code of
Signals.
Example:
"Please use/I will use the International Code of Signals".
2.2.4 Where the message contains instructions or advice, the substance should be repeated in
the reply.
Example:
"Message: Advise you pass astern of me.
Reply: I will pass astern of you."
2.2.5 If a message is not properly received, ask for it to be repeated by saying "Say again".
2.2.6 If a message is received but not understood, say "Message not understood".
2.2.7 If it is necessary to change to a different channel say "Change to channel ...." and wait for
acknowledgement before carrying out the change.
2.2.8 During exchange of messages, a ship should invite a reply by saying "over".
2.2.9 The end of a communication is indicated by the word "out".
Reference documents
- 1974 SOLAS Convention, as amended, chapter IV on Radiocommunications.
- Radio Regulations, Appendix 18, Table of Transmitting Frequencies in the VHF
Maritime Mobile Band.
- Resolution A.917(22), as amended by resolution A.956(23) on Guidelines for the
onboard operational use of shipborne automatic identification systems (AISs).
- Resolution A.918(22) on IMO Standard Marine Communication Phrases (SMCP).