MARCOM 2
MARITIME VHF EXCHANGES
2.0 Introduction
Any conversation at sea, i.e. a ship-to -ship, ship-to-shore or
shore-to-ship exchange, consists of the following stages:
1. MAKING
CONTACT
2. EXCHANGE OF
MESSAGES
3. END
PROCEDURE
The smallest interactive unit (i.e. unit of conversation) in spoken
marine communications is the exchange. It refers to a single topic
and consists of two turns, one held by the controlling station (first
speaker/ship/shore-based station) and the other by the responding
station (second speaker/ship/shore-based station).
A turn represents everything one speaker says or asks ‘at one
go’, i.e. the time between his pressing and releasing the speaker key
on the VHF radiotelephone). The speaker normally ends his turn by
using the word ‘over’ as a signal indicating that he has finished his
turn and that the turn is yielded or given to the hearer, who then takes
the turn (turn-taking).
Two turns referring to a single topic (the subject of
conversation) make a maritime exchange. A single exchange, or
more usually, two or more exchanges on a single or a number of
topics, make a maritime VHF conversation.
The most important part of the turn is the move or act, the
speaker’s contribution to the exchange or success of conversation. A
move or an speech act may be a word, phrase, or a sentence which the
speaker uses in his turn to express his intention, query, request or
purpose of communication (e.g. MAYDAY RECEIVED; WHAT
ARE YOUR INTENTIONS?; WHAT ARE MY BERTHING
INSTRUCTIONS?, etc.).
The principal acts in maritime VHF or other spoken communications are:
QUESTION
ANSWER
INFORMATION
INSTRUCTION
ADVICE
REQUEST
INTENTION
WARNING
QUESTION RECEIVED
ANSWER RECEIVED
INFORMATION RECEIVED
INSTRUCTION RECEIVED
ADVICE RECEIVED
REQUEST RECEIVED
INTENTION RECEIVED
WARNING RECEIVED
These are referred to in SMCP 2001 as MESSAGE MARKERS and
introduce the speaker’s intention or what he is going to say of ask
The primary acts in a normal conversation are:
ACCEPT
ACKNOWLEDGE
AGREE
ANSWER
APOLOGY
CALL-OFF
CHECK
REPLY
CONFIRM
DISAGREE
GREETING
EVALUATE
EXCUSE ME
INFORM
INVITE
REQUEST
OBJECTION
OFFER
OPPOSE
QUESTION
REACT
REPEAT
REJECT
THANK
OTHER SPEECH ACTS / MOVES OR PHRASES
(used in conducting maritime VHF communications are):
WORD or PHRASE
ACKNOWLEDGE
AFFIRMATIVE
ALL SHIPS IN …
(AREA)
BREAK
CALLING
CHANNEL
CONFIRM
CORRECTION
FINAL CALL
GO AHEAD
HAVE A GOOD
WATCH / VOYAGE
HOW DO YOU
READ?
INTERRUPTION
I SAY AGAIN
I AM COMING TO
YOUR ASSITANCE
MAYDAY
MAYDAY RELAY
MESSAGE FOR
YOU
MISTAKE
NEGATIVE
NOTHING MORE
… ON CHANNEL …
OVER
OUT
PAN PAN
MEANING
Let me know that you have received and understood
this message
Yes, or permission granted
I request that all ships receiving this transmission (in the
specified sea area) listen to what follows
I must break (into) this conversation for urgent reasons
I wish to speak to …
Change to channel…....... before proceeding.
My version is _____. Is that correct?
An error / mistake has been made in this transmission
(message indicated). The correct version is ___.
I have finished my operation and wish to stop
communicating
Proceed with your message.
A polite form of ending the conversation, used before the
word OUT.
How well are you receiving me? Do you receive me?
I READ BAD / POOR / FAIR / GOOD/WELL /
EXCELLENT/1…5.
I am being interrupted. I will take action to deal with it.
Used instead of “I repeat”).
Used as a response to an initial distress message if your
ship or station is able to render assistance.
The spoken word for the distress signal.
Is the spoken word for the distress relay signal.
In Radio Traffic: I have a message for you which I
intend to read. Say if you are ready to receive it. - PASS
ON YOUR MESSAGE
There is a mistake in the transmission. The correct
information should be … - CORRECTION: …
No, or that is not correct, or I do not agree.
I have finished my message
I am calling on channel …
My transmission is ended and I expect a response from
you.
I am terminating my transmission. Conversation is ended
and no response is expected,
The spoken word for the urgency signal.
PLEASE
ACKNOWLEDGE
PLEASE READ
BACK
PLEASE SPEAK IN
FULL / SLOWLY
PLEASE SPELL …
PLEASE USE SMCP
PRUDONCE
READBACK
ROGER
ROGER NUMBER
ROGER STANDBY
SAY AGAIN
SECURITE
SEELONCE
SEELONCE
DISTRESS
SEELONCE
FEENEE
SEELONCE
MAYDAY
SORRY
STAND BY ON VHF
CHANNEL …
STANDING BY on ..
Indicate that you have received what I have just said
Read back to me the information that I have just given
READING BACK: …
Do not abbreviate your messages / speak slowly, I have
difficulty in following or understanding
Spell (e.g. your ship's name) using the phonetic alphabet
I SPELL … / I AM SPELLING …
Use SMCP (formerly SMNV) during this conversation
During long distress situations, communications can
resume on a restricted basis. Communication is to be
restricted to ship's business or messages of a higher
priority.
Repeat all of this message back to me exactly as received
after I have given OVER. (Do not use the word
"repeat".)
I have received all of your last transmission. (not
recommended)
I have received your message number…. (not
recommended)
I must pause for a few seconds or minutes, please wait.
(not recommended)
Self-explanatory. (Do not use the word "repeat".)
I SAY AGAIN : …
The spoken word for the safety signal.
Indicates that silence has been imposed on the frequency
due to a distress situation.
Is the international expression to advise that a distress
situation is in progress, This command comes from a
vessel or coast station other than the station in distress.
Is the international expression for a distress cancellation.
Is the international expression to advise that a distress
situation is in progress. The command comes from the
ship in distress.
Polite statement of apology or for having made a
MISTAKE in transmission
Remain on VHF channel …
STANDING BY ON CHANNEL …
Response to “Stand by …” - I agree to keep watch on
VHF channel …
STAY ON
STOP
TRANSMITTING
SWITCH TO VHF
CHANNEL …
AGREE VHF
CHANNEL …
SWITCHING TO
CHANNEL …
VHF CHANNEL …
UNABLE
VHF CHANNEL
AVAILABLE 08
THROUGH 15
THAT IS CORRECT
WHICH VHF
CHANNEL?
THANK YOU
THIS IS …
UNDERSTOOD
UNKNOWN SHIP …
VERIFY
WAIT … MINUTES
WHICH VHF
CHANNEL?
Do not terminate this conversation or change the subject
because I have more to say
Stop transmitting on this channel (a higher priority
transmission going on or to be started)
I suggest that you switch / go / change to channel …
Positive response to the Instruction: ‘Switch to VHF
channel …’
I accept the suggested channel and am just changing to /
going to that VHF channel
I cannot switch to channel …
I can only operate on VHF channels from 8 to 15
(including ch. 8 and ch. 15)
Self-explanatory
Which channel do you suggest ? SWITCH TO VHF
CHANNEL …
Polite statement of gratitude
Used to identify a station. My name (call sign) is …
I have received and understood the information and I
shall read it back to you now. - (optional response:
READBACK IS CORRECT)
I wish to make contact with the ship described. I do not
know its name or call sign (give relative position, type,
colour, course, speed)
Check coding, check text with originator and send
Correct version.
Wait for … minutes and do not terminate
Which channel do you suggest ? SWITCH TO VHF
CHANNEL …
Exercise on phrase markers
(OTHER SPEECH ACTS / MOVES)
(used in conducting maritime VHF communications are):
Write down the VHF/SMCP phrase corresponding to the explanation in the right column:
VHF/SMCP PHRASE
MEANING
Let me know that you have received and understood
this message
Yes, or permission granted
I request that all ships receiving this transmission (in the
specified sea area) listen to what follows
I must break (into) this conversation for urgent reasons
I wish to speak to …
Change to channel…....... before proceeding.
My version is _____. Is that correct?
An error / mistake has been made in this transmission
(message indicated). The correct version is ___.
I have finished my operation and wish to stop
communicating
Proceed with your message.
A polite form of ending the conversation, used before the
word OUT.
How well are you receiving me? Do you receive me?
I READ BAD / POOR / FAIR / GOOD/WELL /
EXCELLENT/1…5.
I am being interrupted. I will take action to deal with it.
Used instead of “I repeat”).
Used as a response to an initial distress message if your
ship or station is able to render assistance.
The spoken word for the distress signal.
Is the spoken word for the distress relay signal.
In Radio Traffic: I have a message for you which I
intend to read. Say if you are ready to receive it. - PASS
ON YOUR MESSAGE
There is a mistake in the transmission. The correct
information should be … - CORRECTION: …
No, or that is not correct, or I do not agree.
I have finished my message
I am calling on channel …
My transmission is ended and I expect a response from
you.
I am terminating my transmission. Conversation is ended
and no response is expected,
The spoken word for the urgency signal.
Indicate that you have received what I have just said
Read back to me the information that I have just given
READING BACK: …
Do not abbreviate your messages / speak slowly, I have
difficulty in following or understanding
Spell (e.g. your ship's name) using the phonetic alphabet
I SPELL … / I AM SPELLING …
Use SMCP (formerly SMNV) during this conversation
During long distress situations, communications can
resume on a restricted basis. Communication is to be
restricted to ship's business or messages of a higher
priority.
Repeat all of this message back to me exactly as received
after I have given OVER. (Do not use the word
"repeat".)
I have received all of your last transmission. (not
recommended)
I have received your message number…. (not
recommended)
I must pause for a few seconds or minutes, please wait.
(not recommended)
Self-explanatory. (Do not use the word "repeat".)
I SAY AGAIN : …
The spoken word for the safety signal.
Indicates that silence has been imposed on the frequency
due to a distress situation.
Is the international expression to advise that a distress
situation is in progress, This command comes from a
vessel or coast station other than the station in distress.
Is the international expression for a distress cancellation.
Is the international expression to advise that a distress
situation is in progress. The command comes from the
ship in distress.
Polite statement of apology or for having made a
MISTAKE in transmission
Remain on VHF channel …
STANDING BY ON CHANNEL …
Response to “Stand by …” - I agree to keep watch on
VHF channel …
Do not terminate this conversation or change the subject
because I have more to say
Stop transmitting on this channel (a higher priority
transmission going on or to be started)
I suggest that you switch / go / change to channel …
Positive response to the Instruction: ‘Switch to VHF
channel …’
I accept the suggested channel and am just changing to /
going to that VHF channel
I cannot switch to channel …
I can only operate on VHF channels from 8 to 15
(including ch. 8 and ch. 15)
Self-explanatory
Which channel do you suggest ? SWITCH TO VHF
CHANNEL …
Polite statement of gratitude
Used to identify a station. My name (call sign) is …
I have received and understood the information and I
shall read it back to you now. - (optional response:
READBACK IS CORRECT)
I wish to make contact with the ship described. I do not
know its name or call sign (give relative position, type,
colour, course, speed)
Check coding, check text with originator and send
Correct version.
Wait for … minutes and do not terminate
Which channel do you suggest ? SWITCH TO VHF
CHANNEL …
Exercise 2.0
The following four stages in a marine VHF conversation are in the
wrong order. Rewrite the stages in the correct sequence:
Correct sequence of stages:
AGREE A WORKING VHF 1.
CHANNEL
2.
EXCHANGE MESSAGES
3.
TERMINATE
4.
MAKE CONTACT
MARCOM 2.1 – MAKING CONTACT
Contact making includes the following steps:
CALLING STATION
1.
2.
3.
RESPONDING STATION
initial call
response to initial call
indicating the working
channel
4.
agreeing/disagreeing
with the working channel
switch-over procedure
5.
switch-over procedure
Exercise 2.1
The steps of the Making Call procedure below is in the wrong
sequence. Rewrite the steps in the correct order in the Table
2.1:
-
response to initial call
indicating the working channel;
agreeing/disagreeing with the working channel;
initial call;
switch-over procedure
Table 2.1
Calling Station
1
2.
3.
4.
5.
Responding Station
Exercise 2.1.1 Initial call
Initial call contains the following:
a) Address (the station you are calling; two or three times)
b) Identify (your own station)
c) (state the) VHF channel (on which you are calling)
d) Over. (turn-giving signal)
Case 1. Single station call - name of the ship being called is known:
Calling Station:
RIJEKA RADIO, RIJEKA RADIO, RIJEKA RADIO
THIS IS MARLIN DLG3Y, MARLIN DLG3Y.
(CALLING) ON CHANNEL 16.*
OVER
Responding Station:
MARLIN DLG3Y, MARLIN DLG3Y.
THIS IS RIJEKA RADIO, RIJEKA RADIO
(ON VHF CHANNEL ONE-SIX)**
OVER
* also COME IN, PLEASE - (frequently used; not suggested by SMCP)
** also GO AHEAD
(optional)
Role-play 1:
Work in pairs with student A playing the role of Calling Station and
student B playing the role of Responding Station:
Calling Station
SEA BREEZE TRG6
GENTLE OAK BRI3
DARK LADY NSCK
MALINSKA HRLU
GENOA PRIDE IASM9
GREAT CIRCLE PSWE
NEWCASTLE CXQZ
Responding Station
NEWPORT PILOT STATION
JEDDAH COAST STATION
SANTIAGO PORT CONTROL
GOTHENBURG VTS
TARIFFA RADIO
LLOYD’S SIGNAL STATION
SAVANNAH COASTGUARD
Case 2. Single station call - name and call sign of the ship/station is
known:
Calling station
SEA BASS VC3G, SEA BASS VC3G, SEA BASS
VC3G,
THIS IS NEWHAVEN RADIO, NEWHAVEN RADIO,
ON CHANNEL 16
OVER
Responding station
NEWHAVEN RADIO, NEWHAVEN RADIO
THIS IS SEA BASS VC3G, SEA BASS
VC3G, SEA BASS VC3G,
ON CHANNEL 16
OVER
Role-play 2:
Work in pairs with student A playing the role of Calling Station and
student B playing the role of Responding Station:
Calling Station
GOTHENBURG VTS
JEDDAH COAST STATION
BARCELONA, JKLD
MADRAS II, IVCX
SWORDFISH, EWQO
RIJEKA RADIO
JEDDAH COAST STATION
Responding Station
SEA BREEZE TRG6
GENTLE OAK BRI3
DARK LADY NSCK
MALINSKA HRLU
GENOA PRIDE IASM9
GREAT CIRCLE PSWE
NEWCASTLE CXQZ
Case 3 General Call - name of the station/ship is unknown:
Example 1:
CALLING STATION
ALL SHIPS, ALL SHIPS, ALL SHIPS
IN SEA AREA BAY OF RIJEKA,
CALLING UNKNOWN SHIP, TYPE: TANKER,
HULL COLOUR: BLUE, COURSE: 158 DEGREES,
SPEED: 14 KNOTS.
THIS IS RIJEKA RADIO, RIJEKA RADIO.
OVER
or
OVER
ALL STATIONS, ALL STATIONS, ALL STATIONS
IN SEA AREA MAAS APPROACH,
CALLING UNKNOWN SHIP IN POSITION:
BEARING: 1-8-5 DEGREES FROM BOUY B15
DISTANCE: 0.6 MILES.
THIS IS ROTTERDAM VTS.
OVER.
RESPONDING STATION:
ROTTERDAM VTS. ROTTERDAM VTS.
THIS IS SEA URCHIN, N-W-F-9,
IN POSITION:
BEARING: 1-8-5 DEGREES FROM PUNTA
STELLA, DISTANCE: 4.6 MILES.
OVER.
or
CONTAINER VESSEL ON MY PORT BOW*,
CONTAINER VESSEL ON MY PORT BOW,
COURSE: 172 DEGREES, SPEED: 12 KNOTS.
THIS IS MOTOR TANKER SHELLFISH, MOTOR
TANKER SHELLFISH ON YOUR STARBOARD BOW.
OVER.
* Though very frequent in real situations at sea, this type of VHF
communication is discouraged by SMCP 2001 and COLREGS 1972. Instead,
vessels should fully observe the Collision Regulations.
Ex. 2.2
Role play 3 – pair work
1
2
3
4
5
6
7
CALLING Station
RESPONDING Station
NEWPORT
PILOT Newport Waterway; VLCC,
STATION
yellow funnel; 145 degr 1.6 NM
from Point Mike
(SEA BREEZE TRG6)
JEDDAH
COAST Jeddah VTS, ro-ro ship, blue;
STATION
course and speed: 269 degrees T,
17 miles per hour
(GENTLE OAK BRI3)
SANTIAGO
PORT Gulf of Santiago, cruise ship,
CONTROL
white, red funnels; 89 degrees
from Cabo Holy Spirit, 2,5
nautical miles;
(DARK LADY NSCK)
GOTHENBURG VTS Gothenburg
VTS,
Container
vessel, six miles from Mow Point,
steering a course of 231°, at a
speed of approximateIy 8 knots
(MALINSKA HRLU)
passenger ferry, white hull with
TARIFFA RADIO
green funnels. 6 miles from
Tariffa harbour entrance, steering
southwest, 10 knots
(KORKYRA NIGRA HRZC)
LLOYD’S
SIGNAL LASH type, steering a course of
STATION
50°, at a speed of 15 knots, sea
area Masekar.
(GREAT CIRCLE PSWE)
SAVANNAH
tanker: hull colour white with
COASTGUARD
black funnel steering 85°, at a
speed of 10 knot
(NEWCASTLE CXQZ)
Coastal Radio Traffic Lists
Example on Channel 16:
ALL STATIONS, ALL STATIONS, ALL STATIONS
THIS IS
TOFINO COAST GUARD RADIO
(repeated up to 3 times)
FOR TRAFFIC LIST, LISTEN (SWITCH
TO) CHANNEL 26
TOFINO COAST GUARD RADIO
OUT
- Define the term ‘traffic list’
- Who transmits traffic lists?
- What should you (Master/OOW) do when the info on the traffic list
is transmitted?
2.1.2 Responding to initial call
(a) address the station,
(b) identify your own station), and
(c) finish your turn by saying OVER.
- You can advise the calling station to proceed with the message
by means of the words GO AHEAD, or,
- if you are occupied, by saying STAND BY followed by the
estimated number of minutes until your reply.
- Do not ignore the call
e.g.
MARLIN DL2352.
THIS IS
RIJEKA RADIO
GO AHEAD
OVER
Replying to Calls when Information Is Missing
- if the identity of the calling station is uncertain:
STATION CALLING SPLIT RADIO
SAY AGAIN
OVER
2.1.3 Switching to a Working Channel
SWITCH TO (VHF CHANNEL) …
Other phrases commonly used are:
CHANGE TO …
GO TO …
Examples:
Calling Station
PULA, HR5432.
THIS IS ALGECIRAS RADIO.
SWITCH TO (VHF CHANNEL) 2 – 5
OVER
Responding Station
ALGECIRAS RADIO.
THIS IS PULA, HR5432.
AGREE VHF CHANNEL 2 - 5
OVER
or
ALGECIRAS RADIO.
THIS IS PULA, HR5432.
AGREE: SWITCHING TO
VHF CHANNEL 2 - 5
OVER
If the suggested channel is not available use the phrase:
VHF CHANNEL … UNABLE.
and then suggest another channel:
VHF CHANNELS AVAILABLE: …
or
VHF CHANNELS AVAILABLE: … THROUGH …
Example:
ALGECIRAS RADIO.
THIS IS PULA, HR5432.
VHF CHANNEL AVAILABLE: 2 – 4.
OVER
or
ALGECIRAS RADIO.
THIS IS PULA, HR5432.
VHF CHANNELS AVAILABLE: 2 – 4
THROUGH 2 - 8.
OVER
If the VHF channel has not been specified by the Controlling Station, the other station may
ask the following:
QUESTION: WHICH VHF CHANNEL?
MARCOM 2.3 – AGREEING TO THE WORKING CHANNEL
Exercise 2.2 Role play - Pair work
CALLING STATION
RESPONDING STATION
1
Rijeka Radio, suggests Ch. «Marlin» RTU5 agrees to change to
24
Ch. 24
Rijeka Radio, suggests Ch. Your VHF channel 19 is not in
19
operation. Say that you can speak on
channnels from 09 to 15
Marlin RTU5 says that her Rijeka radio asks which channel is
channel available is 17
available
2
Dubai Radio, suggests Ch.
18
Rostock Radio suggests
Ch. 11
«Codfish» LPUJ says that
her channel available is 17
«Codfish» LPUJ repeats
that her channel available
is 17
3
Santiago Radio, suggests
Ch. 11
Perth Radio suggests Ch.
22
«Seawolf» MZGR says
that her channel available
is 23
«Codfish» LPUJ repeats
that her channel available
is 23
Perth Radio suggests Ch.
14
«Codfish» LPUJ agrees to change to
Ch. 18
Your VHF channel 11 is not in
oparation. Say that you can
communicate on channnels from 12
to 20
Dubai radio asks which channel is
available
Dubai Radio agrees
«Seawolf» MZGR agrees to change
to Ch. 11
Your VHF channel 22 is not in
oparation. Say that you can
communicate on channnels from 12
to 20
Perth Radio asks which channel is
available
Perth Radio agrees
«Seawolf» MZGR agrees to change
to Ch. 14
MARCOM 2.3 – EXCHANGE MESSAGES
MARCOM 2.4 – CLOSING EXCHANGES
OTHER
A station may say Nothing more before ending a transmission, if it has no further messages to
transmit. What will it say if it does wish to pass on further messages?
(NB: Model answers are printed at the end of the Exercises to Section 2.)
READABILITY
MESSAGE CHECKS, etc.
1.4.3 Message Checks
In the course of VHF exchanges it is often necessary to check mutual understanding, i.e. if the
other station follows the conversation, or when we have made a mistake during the
transmission. This is done by the use of the following SMCP phrases:
UNDERSTOOD:
MISTAKE … CORRECTION
STAY ON
NOTHING MORE
SAY AGAIN
READ BACK
- How do you read?
- Wait -- -- minutes.
- Please spell
- Please use SMCP 2001
- Sorry
- Thank you
- VHF channel -- -- unable.
END PROCEDURE: Closing exchanges:
Thank you for your cooperation.
Have a good watch.
2. Exchange of Messages
In the message exchange procedure the following message markers (i.e.
words introducing the content and purpose of the message) are:
Message Marker
QUESTION
INSTRUCTION
ADVICE
REQUEST
INFORMATION
WARNING
INTENTION
Examples:
QUESTION: What are your
intentions?
Answer to Message Marker
ANSWER
(INSTRUCTION RECEIVED)
(ADVICE RECEIVED)
(REQUEST RECEIVED)
(INFORMATION RECEIVED)
(WARNING RECEIVED)
(INTENTION RECEIVED)
ANSWER: I intend to alter course
t
o
starboard
WARNING: Buoy number: one five unlit
ADVICE: You must anchor clear
of fairway
INFORMATION: The fairway
entrance is: position: bearing 1-3-7
degrees true from North Point
Lighthouse, distance: 2 decimal 3
miles
REQUEST: Please supply bunkers:
quantity: 3 thousand metric tonnes
WARNING RECEIVED: Buoy
number: one - five unlit
ADVICE RECEIVED: I shall
anchor clear of fairway
INFORMATION RECEIVED: The
fairway entrance is: position:
bearing 1-3-7 degrees true from
North Point Lighthouse, distance: 2
decimal 3 miles
REQUEST RECEIVED: Supply
bunkers: quantity: 3 thousand
metric tonnes
INSTRUCTION: Steer course two - INSTRUCTION RECEIVED: I
two - three degrees true. reason: to shall steer course two - two - three
comply with traffic separation
degrees true to comply with traffic
scheme
separation scheme
INTENTION: I intend to reduce
INTENTION RECEIVED: You
speed, new speed: eight knots
intend to reduce speed, new speed:
eight knots
For further information on message exchanges, e.g. communications on arrival
at a port, berthing and unberthing, etc. see units 18-23.
3. End Procedure
In the end procedure the conversation is terminated, by confirming the
previous turn: UNDERSTOOD or by saying: NOTHING MORE or GOING
BACK TO CHANNEL ONE SIX or I'LL GIVE YOU A CALL BACK WHEN ON
BUOY DELTA ONE TWO, and by adding a polite greeting:
HAVE A GOOD WATCH
HAVE PLEASANT VOYAGE TO
Finally, the closing phrase OUT or OVER AND OUT is used; e.g.:
CALLING STATION
Seaside VTS. This is Aries.
Your message understood.
Nothing more. Thank you.
Have a pleasant voyage to
Ceuta. Over.
RESPONDING STATION
Aries. This is Seaside VTS.
Thank you. Have a good
watch. Over and out.
For further information and practising maritime VHF communications see
SEASPEAK 1985, SMNV 1977/1985 and SMCP 1997.