Page 49 - NAVAL SCIENCE 3 TEXTBOOK

54 NAVAL KNOWLEDGE

and collision warnings, and wartime communications between 9. How is tactical data sent between ships and aircraft in today's
ships in convoy. Navy?
A waterborne sound communications method called Gertrude 10. How would your full name be sent in Morse code?
uses an underwater telephone system associated with submarine or
11. What are the main Navy visual communications methods?
destroyer sonar equipment. It can communicate either by continu-
12. "Vhat is the principal use of f1aghoist?
ous wave (CW) or voice. It is limited in range and not very secure.
Pyrotechnics are used for emergency signals. They are mainly 13. A. What are three ways of communicating by flashing light?
of the "fireworks" variety: pistol flares; colored shell bursts, includ- B. What is the advantage of the Nancy system?
ing parachute flares; aircraft parachute flares; Roman candles; and
14. A. What is semaphore?
a number of colored f1oat- and smoke-type flares. The color of the
B. How can it be used at night?
flare determines the meaning of the signal.
Distress signals indicating that a ship or person needs help are 15. A. What sound communications are used by ships, and under
what conditions are they used?
covered in the Rules of the Road and Maneuvering Board unit in
this text. All ships at sea are required to maintain a listening watch B. What is the Gertrude system?
on radio distress frequencies at all times. It is a fundamental law of
the sea that any vessel that sees or hears a distress signal must render
CRITICAL THINKING
assistance if at all possible.
1. Research satellite communications, and describe how
this communications system affects voice and Internet
communications.
STUDY GUIDE QUESTIONS 2. Do you think cell phone technology is good for transmitting
inlportant information on the battlefield? Support your
1. A. What is "communications"?
answer.
B. What is "naval communications"?
2. Why are effective communications in the Navy so important?
VOCABULARY
3. What three qualities must naval communications have?
4. What are the main and secondary functions of naval encryption decryption
telecommunications? tactical data link radiotelephone
international Morse code telecommunications
5. What are the largest of the Navy's communications facilities
called? circuit discipline f1aghoist
phonetic alphabet Gertrude
6. Which officer is in charge of a ship's communications
pyrotechnics Nancy
organization?
semaphore
7. A. What is a radiotelephone?
B. What alphabet is used for voice communications by radio?
8. What are communications satellites?