Signaling
Signaling by Morse Code
Signalling by Morse Code
Morse symbols
Alphabet
Numerals
Procedure
Signals
Parts of a
signal made by flashing
The call. It
consists of the general call or the identity signal of the station to be
called. It is answered by the answering signal.
The identity. The
transmitting station makes “DE” followed by its identity signal or name. This
will be repeated back by the receiving station, which then signals its own
identity signal or name. This will also be repeated back by the transmitting
station.
The text. This consists of plain language or code groups. When code groups are to be used they should be preceded by the signal “YU”. Words of plain language may also be in the text, when the signal includes names, places, etc. Receipt of each word or group is acknowledged by “T”.
The ending. It
consists of the ending signal
“AR” which is answered by “R”.
If the entire text is in plain language the same
procedure is to be followed. The call and identity may be omitted when two
stations have established communications and have already exchanged signals.
Procedure for sending a message to an unknown ship in
Plain language or in code
The General
Call signal (including call to an unknown station):
“AA AA AA” etc. is made
to attract the attention when wishing to signal to all stations within visual
signaling distance or to a station whose name or identity is not known.
The call is continued until the station addresses.
Once the station signaled to has answered by signaling:
The Answering signal “TTTT” etc. is made to answer the
call and it is to be continued until the transmitting station ceases to make
the call.
The transmission starts with the signal “DE” followed
by the name or identity signal of the transmitting station.
If the text is in plain language then the code “YU”
need not be used, but if the message in plain text does contain codes then the
code “YU’ has to be transmitted at the beginning of the text message.
After each word or group of words is transmitted the receiving station should signal “T”, meaning that the word or group has been received.
The ‘repeat’ signal
If the receiving station has not received a part of
the message then it would send a signal “RPT” meaning REPEAT WHAT YOU HAVE
SENT.
The repetition
signals AA, AB, WA, WB and BN
If only a part of the message has not been received
properly then it would send as follows:
RPT AA: Repeat all after
RPT WB: Repeat word before
RPT BN: Repeat word between
Example:
“Repeat all before group Kilogrammes” – RPT AB
Kilogrammes
“Repeat all between words ‘boats’ and ‘survivors’” –
RPT BN boats and survivors
The transmitting station on completing of transmission
may send the signal RPT and then commence re-transmitting the entire message.
If however the transmitting station transmits RPT at
the end of its transmission and then does not re-transmit then it would mean
that it is requesting the receiving station to repeat the entire transmission
of what it has received.
The ‘erase’ signal when sending or receiving
The Erase signal “EEEEE” (group of 5 E’s): is used to
indicate that the last group or word was signaled incorrectly. It is to be
answered with the erase signal. When answered, the transmitting station will repeat
the last word or group, which was incorrectly signaled, and then proceed with
the remainder of the transmission.
Important:
If the receiving station receives the message
correctly but is unable to understand what has been sent, then it would send the
signal by code (ZL) for it to mean, “your signal has
been received but not understood”.
A correctly received REPETITION is acknowledged by the signal “OK”. The same signal may
be used as an affirmative (YES) answer to a question (“It is correct”).
The Ending signal “AR” is used in all cases to
indicate the end of a signal or the end of the transmission. The
receiving station answers with the signal “R” (“Received” or “I have received
your last signal”).
If the transmitting station sends the signal “CS” it
means that it is requesting the name or identity signal of the receiving
station.
Use of the
waiting signal AS
The signal “AS” is used both as a waiting signal as
well as a period signal to separate groups of words.
If the signal “AS” is made independently or after the
end of a signal then it means that the other station must wait for further
communications.
If the signal “AS” is inserted between word groups
then it means that it is being used as a separator between the groups of words.
The use of
the procedure signals C, N (or NO), RQ
The signal “C” should be used to indicate an
affirmative statement or an affirmative reply to an interrogative signal.
Meaning, it is used when stating in the positive by the transmitting station or
when answering positively to a statement by a receiving station.
The signal “RQ” should be used to indicate a question.
For a negative reply to an interrogative signal or for
a negative statement, the signal “N” should be used.
Note: When the signals “N” or “RQ” are used to change
an affirmative signal into a negative statement or into a question,
respectively, they should be transmitted after the main signal.
Example:
To transmit the following:
“Boat is not coming to you” – CY N
“Is boat on board?” – CW RQ
Important: The signals “C”, “N” and “RQ” cannot be
used together with single letter signals.
The meaning
and use of YU, YV, YZ
YU – I am going to communicate with your station by
means of the International Code of Signals
YV – The groups which follow are from the International
Code of Signals.
YV 1 – The groups which follow are from the local code
YZ – The words which follow are in plain language.
Recommendations on sound signaling
Owing to the nature of the apparatus used (whistle,
siren, fog-horn, etc.) sound signaling is necessarily slow. Moreover the misuse
of sound signaling is of a nature to create serious confusion at sea. Sound
signaling in fog should therefore be reduced to a minimum. Signals other than
the single letter signals should be used only in extreme emergency and never in
frequented navigational waters.
The signals should be made slowly and clearly. They
may be repeated, if necessary but at sufficiently long intervals to ensure that
no confusion can arise and that one-letter signals cannot be mistaken as two –
letter groups.
Masters are reminded that the one-letter signals of
the Code, which are marked with an (*), when made by sound, may only be made in
compliance with the requirements of the International Regulations“ for Preventing Collisions at Sea. Reference is also made
to the single – letter signals provided for exclusive use between an ice-
breaker and assisted vessels.
Single‑letter signals in addition to the single letter signals as per the InterCode
International Regulations for Preventing Collisions at
sea
One short blast to mean “I am altering my course to
starboard”;
A vessel nearing a bend or an area of a channel or
fairway where other vessels may be obscured by an intervening obstruction shall
sound one prolonged blast. Such signal
shall be answered with a prolonged blast by any approaching vessel that may be
within hearing around the bend or behind the intervening obstruction.