APPENDIX II
FLASHING LIGHT AND SEMAPHORE DRILLS
FLASHING LIGHT
LEARNING OBJECTIVE: List tips on sending
and receiving flashing light and on light
qualifications.
International Morse code, a series of dots and
dashes representing letters and numerals, is the
standard for all flashing light and radio CW
communications. The original code system was
worked out in 1832 by Samuel F. B. Morse.
You must know international Morse code before
you can use flashing light equipment effectively.
Figure AII-1 shows the alphabet, numbers, and
punctuation with the code equivalent. Basically, the
code consists of 44 sight patterns: 26 letters, 10
numerals, and 8 punctuation marks. Each sight pattern
(mental picture) except for punctuation contains from
one to five dots or dashes (dits or dahs) or a
combination of both, representing a letter or numeral.
Except for the left parenthesis and slant/oblique
stroke, punctuation sight patterns consist of dots and
dashes in groups of six.
Experience has proved that the best way for most
communications personnel to learn code is by
“wholes.” For example, the Radioman is taught to
relate whole tonal sounds to characters. Similarly, the
Signalman should learn by whole sight patterns. Don't
break each character into dits and dahs that you have
to count. Try, instead, to learn each character as a
complete mental picture. When you see one dit and
one dah, say and think the letter A. Don't count them one
dit, one dah, and then conclude that it is the letter A.
The best tip you will ever get on how to be a good
Signalman is this: PRACTICE—don't neglect it!
Practice is the stepping-stone to success. When you
see a good Signalman sending and receiving a
message on the light, you can rest assured that he or
she had plenty of practice.
Once you memorize the code, ask one of the more
experienced Signalman to send to you, using a blinker
card, a multipurpose light, or even one of the
searchlights. For the first few times, have the sender
to tell you in advance what character he or she is going
to send so you can get use to how that particular sight
pattern looks. When you are reasonably sure you have
the sight patterns memorized, ask the sender to send a
character without telling you what it is, and you call
out the character. If you miss, ask the sender to tell you
at once what character it was and ask him or her to
repeat it. After you gain considerable practice on
individual patterns, have some code groups consisting
of random characters sent to you. If you notice that
you confuse a few characters with others or that you
seem to miss them more often than the rest, devote
more time to those characters.
Practice these code groups as starters:
AFARF
EBBEU
NSPNP
LMZLM
ARFQZ
FEKUG
RBAPU
GVMCD
UQIWT
EHOXA
YSFTI
KNPUR
UFIEI
IAZIP
CBRIE
ULXWK
You can make up all sorts of combinations yourself.
Just be sure they are code groups, not ordinary words.
At this stage of the game, there is a definite reason why
you should not attempt plain language drills: You may
fall into the habit of anticipating the rest of the word or
even the next logical word in the text.
When you become really proficient in receiving
code groups, only then should you progress to plain
language. Even in these drills, try not to anticipate the
next letter or word. You will be wrong more often than
right, and you will find when you guess wrong you
become confused and miss the entire word.
Anticipating is a bad habit.
TIPS ON SENDING FLASHING
LIGHT
After you become fairly adept at receiving, try
sending code. You will find this phase a bit easier.
Keep in mind, however, that there is a definite physical
limitation to the speed with which flashing light can
be sent and still be readable. Depending upon the skill
of the operator, the 12-inch Navy signal searchlight
can be used to send up to 15 words a minute.
NEVER SEND FASTER THAN YOU CAN
RECEIVE. If you transmit a message at 10 words a
AII-1
