Flag Hoist Signaling
International Morse Code
The most common use of the International
Letter character
Code of Signals is visual signaling using code
a · –
flags (see the back cover). A set of flags con-
b – · · ·
sists of 26 flags for the letters of the alphabet,
c – · – ·
ten number pennants, three substitute pen-
d – · ·
nants, and the answering pennant (the U.S.
e ·
Navy uses a fourth substitute and calls them
f · · – ·
all “repeaters”). The substitutes are necessary
g – – ·
because a set contains only one flag for each
h · · · ·–
letter and some flag hoists require repetitions
i · ·
of one or more letters.
j · – – –
The first substitute always repeats the up-
k – · –
permost signal flag in the group. The second
l · – · ·
substitute always repeats the second and the
m – –
third substitute repeats the third signal flag,
n – ·
counting from the top of that group of flags
o – – –
which immediately precedes them. No sub-
p · – – ·
stitute can ever be used more than once in
q – – · –
the same group.
r · –·
Flag hoists are read from the top flag or
s · · ·
pennant downward; if there is more than one
t –
hoist from a single spreader or yardarm, each
u · ·
hoist is read in turn from outermost inward.
v · · · –
The International Morse Code
w · – –
x – · · –
nals
Letters, numerals, and punctuation marks
y – · – –
S
ig
are signaled in the Morse code by combina-
z – – · ·
tions of dots and dashes. Letters have from
one to four dots or dashes, numerals have
Numeral character
five, and punctuation marks have six. The
1 · – – – –
dots and dashes, and the spaces between
2 · · – – –
them, are defined in terms of units. A dot is
3 · · · – –
one unit in length and a dash is three units.
4 · · · · –
omms
The space between the dots and/or dashes
5 · · · · ·
C
within a character is one unit; the space be-
6 – · · · ·
tween characters is three units; and the space
7 – – · · ·
between words is five units. The length of
8 – – – · ·
any unit is set by the method of signaling,
9 – – – – ·
which is much longer in sound or flashing
0 – – – – –
light than radiotelegraphy.
Regardless of the method of signaling, you
should not try to send at a speed greater
Flashing Light Signaling
than your abilities will allow you to do
Signaling by flashing light is carried out by
clearly. You should also not send at a speed
using Morse Code. It is necessary to practice
greater than that at which you can receive,
sending and receiving, in order to be able to
lest you find yourself unable to keep up with
communicate with another vessel, up to sever-
the other operator.
al miles distant, either day or night. Proficien-
Today, Morse Code is most commonly seen
cy at Morse Code is also required for amateur
as the transmission of radar beacons, which
(ham) radio licenses. Practice tapes and flash
display a Morse Code signal on the receiving
cards are available from several sources.
radar screen.
Your boat’s searchlight, or even a flashlight,
will work. Lights are produced with the ca-
pability of sending a Mayday signal (SOS)
automatically. These may be used to satisfy
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