Visual Communications

1
Visual Communications
2
Lesson Overview

• Visual Comm Methods
• Flag Hoist
• Semaphore
• Flashing Light

• Signal Book
• Organization
• Decoding Messages
• Encoding Messages

3
Visual Communication Methods

• 3 Types
• Flag Hoist
• Semaphore
• Flashing Light

4
Flag Hoist
5
Flag Hoist

• Rapid
• Accurate
• Allows a more uniform execution of maneuver
• Daylight use only

6
Flags

• 68 Flags in Allied Flag Bag
• 26 Alphabet Flags
• 10 Number Flags
• 10 Number Pennants
• 18 Special Flags and Pennants
• 4 Substitutes

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Alphabet Flags
8
Numeral Flags
9
Numeral Pennants
10
Special Flags
11
Substitutes
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Hoist

• Signal consisting of one or more flags on one or
  more halyards

Turn
Starboard
Nine
13
Display

• A complete signal or group of signals

Corpen
Speed
Starboard
V
Nine
Two
Five
14
Reading Flag Hoists
1
2
3
4
5
6
Port to Starboard Outboard to Inboard Top to
Bottom
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States of a Flag Hoist
Hauled down
16
Semaphore
17
Semaphore

• No equipment required
• Faster than flashing light
• More secure than flashing light
• Very short range
• Day or nighttime use

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Flashing Light
19
Flashing Light

• 2 Types
• Directional
• Non-Directional
• Directional - Day or night use
• Searchlight pointed at receiver
• Non-directional - Night use only
• Yardarm blinkers
• Infrared blinkers - read using NVGs

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Signal Book
21
Signal Book

• Used primarily with
• flaghoist
• radio
• 3 sections
• Instructions (Ch 1)
• Signals (Ch 2-33 used to decode)
• Index (used to encode)

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Decoding Signals
TL66-1

• Look in Tactical (TL) chapter (Ch 27) of signal
  book.
• Find TL66
• Decode signal
• Patrol Harbor Entrance

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Decoding More Signals
1
2
3
4
5
6
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Decoding More Signals

• 1. FORM B
• 2. DESIG N3R
• 3. B CORPEN 040
• 4. A SPEED 10
• 5. W SPEED 25
• 6. CG9

• Form a column in quickest sequence on ship
  indicated (N3R) at standard distance
• Base course 040
• Base speed 10kts
• Stationing speed 25kts
• Alter course as necessary to clear obstruction in
  channel.

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Executing Signals

• Sender

• Receiver

Execute signal Haul down signal
Receiver understands message Closes up signal
Sender sends message Closes up signal
Receiver receives message Repeats signal at the
dip
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Executing Signals

• Sender
• Send signal
• Close up signal
• Execute signal
• Haul down signal

• Receiver
• Received signal
• Signal at the dip
• Understand signal
• Close up signal
• Executing signal
• Haul down signal

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Governing Pennants / Groups

• Modify a basic signal
• 3 Pennants
• Preparative
• Interrogative
• Negative
• 16 Groups (BA - BZ)

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Governing Pennants / Groups
GA7-2

• Land the waterborne landing forces.

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Governing Pennants / Groups
PREP GA7-2

• Prepare (to) land the waterborne landing forces.

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Governing Pennants / Groups
INT GA7-2

• Are you land(ing) the waterborne landing forces?

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Governing Pennants / Groups
NEGAT GA7-2

• Do not land the waterborne landing forces.

32
Governing Pennants / Groups
BH GA7-2

• Request permission to land the waterborne landing
  forces.

33
Governing Pennants / Groups
BB GA7-2 BZ

• Landing (waterborne forces) completed
• Well Done

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Substitute Flags

• Used to prevent repetition of flags in the same
  hoist.

35
Indicating Time

• Used after a basic signal
• Tango flag
• Numbers representing time
• Defers execution of a signal until the indicated
  time (instead of executing when signal is hauled
  down)

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Indicating Time

• T before numbers (T1835)
• Start action no earlier than 1835
• T after numbers (1835T)
• Finish action no later than 1835
• T between numbers (1935T1835)
• First number is the finish no later than, Last
  numer is the start no earlier than

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The Time

• Two digits hour
• 19 1900
• half-hour Answer pennant
• 16 Answer 1630
• Four digits normal expression of time
• 1825 1825

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Indicating Time

• Tango signal only affects the signal
  immediately preceding.

SPEED 25 TURN STBD 9 T14
39
Indicating Time

• Add Bravo Tango to group signals to be affected
  by the Tango signal

BT SPEED 25 TURN STBD 9 T14
40
Maneuvering Signals

• 6 Pennants
• Corpen
• Turn
• Formation
• Screen
• Speed
• Station

Each pennant has its own chapter in the signal
book. Look in appropriate chapter and decode the
signal.
41
Description Signals

• Indicated by the DESIG pennant.
• All flags grouped with this pennant are to be
  interpreted literally.
• Used only when there is no other way to express a
  signal.

42
Emergency Signals

• Indicated by the EMERG pennant.
• Execute signal as soon as you understand.
• Repeat signal to other ships.

43
Single Flags and Pennants

• Look up in single flag and pennant chapter
  (chapter 2)
• Common Signals

44
Answer (Code) Pennant

• Answer - used to indicate fractions or decimals.
• Code - prefaces all signals from Pub 102
  International Code book - used to communicate
  with merchants

TURN STBD 4 ANS
Turn starboard 45
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Encoding Signals

• Use index to find the basic signal
• Turn to the indicated basic signal and encode.
• Recover man overboard.
• TL41-13

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QUESTIONS ????