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