Lights, Fog Signals & Buoyage
Buoyage Module
Lights, Fog Signals & Buoyage
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Lights, Fog Signals & Buoyage
Range
During this lesson we will cover the
following:
 The IALA buoyage system Region A.
 The general & local direction of buoyage.
 The characteristics of the different buoys
& lights used in this system.
 Abbreviations used on charts.
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Lights, Fog Signals & Buoyage
Objectives






By the end of this lesson you will be
able to:
Identify lights, fog signals, and IALA Buoyage
System (Region A) by day and night.
State the meaning of and identify general light
characteristics
Use ALLFS to a basic level
State the use and limitations of fog signals
Determine the meaning of and be able to pass
the safe side of IALA Buoyage (Region A)
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Lights, Fog Signals & Buoyage
IALA

International Association of Lighthouse
Authorities (IALA)

Non-governmental body
recommends improvements to
navigational aids based on the latest
technology

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Lights, Fog Signals & Buoyage
IALA BUOYAGE REGIONS “A” & “B”
A
A
B
1973 IALA met and divided the World into
two Buoyage regions - A & B.
Regions A & B differ by which side lateral
marks are placed.
We are interested in Region A
B
B
A
A
B
A
B
A
B
A
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A
A
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Lights, Fog Signals & Buoyage
The IALA System







The system applies to all fixed and floating
marks, other than lighthouses and sector lights.
It serves to indicate the following:
Sides and centrelines of navigational channels
Navigational channels under fixed bridges
Natural dangers and other obstructions such as
dangerous wrecks.
Areas in which navigation may be subject to regulation
Other features of importance to the Mariner
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Lights, Fog Signals & Buoyage
IALA Buoyage system A






To meet the requirements of the system
five different types of mark are provided.
Lateral
Cardinal
Isolated danger
Safe water
Special marks
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Lights, Fog Signals & Buoyage
Lateral Marks


Lateral marks are generally used for well defined
channels in conjunction with direction of Buouyage.
They indicate the limits of channels on the port and
starboard sides
Channel
DIRECTION
OF BUOYAGE
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Lights, Fog Signals & Buoyage
Direction of Buoyage


Local Direction of Buoyage - The direction taken by the Mariner
when approaching a harbour, river, estuary or other waterway from
seaward.
IALA A & B - entering harbour, port hand buoys on the port side and
starboard in the starboard side.
Channel
DIRECTION
OF BUOYAGE
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Lights, Fog Signals & Buoyage


General Direction of Buoyage - The direction determined by the Buoyage authorities,
based whenever possible on the principle of following a clockwise direction around
continents.
At sea around the British Isles its general direction is SW to NE
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Lights, Fog Signals & Buoyage
Starboard Lateral Marks
Colour - Green
Shape - Cone, pillar or spar
Topmark - Single green cone
Retroreflector - Green band or triangle
Light - (When fitted) May have any
Rhythm except 2+1 some
examples are given below:
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Continuous-quick light
Q.G
Single-flashing light
Fl.G
Long-flashing light
LFl.G
Group-flashing light
Fl(2)G
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Lights, Fog Signals & Buoyage
Port Lateral Marks
Colour - Red
Shape - Can, pillar or spar
Topmark - Single Red can
Retroreflector - Red band or square
Light - May have any Rhythm except
(2+1) some examples are given
below:
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Continuous-quick light
Q.R
Single-flashing light
Fl.R
Long-flashing light
LFl.R
Group-flashing light
Fl(2)R
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Lights, Fog Signals & Buoyage
Cardinal Marks
N
W
POINT
OF
INTEREST
S
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E
Note. Topmarks always point
towards black band
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Lights, Fog Signals & Buoyage
Cardinal marks are used are used in conjunction with a compass
to indicate where the Mariner may find the best navigable water
Pass to the west of the cardinal
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Lights, Fog Signals & Buoyage
North Cardinal Mark
Colour
Top Black
Bottom - Yellow
Topmark
Two black cones
points upwards
N
W
Retroreflector
Blue over Yellow band
POINT
OF
INTEREST
S
E
Shape
Pillar or spar
Light
Colour - White
Rhythm - Q or VQ
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Lights, Fog Signals & Buoyage
East Cardinal Mark
Topmark
Two black cones
points away
Colour
Top Black
Middle - Yellow
Bottom - Black
Retroreflector
Two Blue bands
N
W
POINT
OF
INTEREST
E
S
Shape
Pillar or spar
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Light
Colour - White
Rhythm - Q(3) or VQ(3)
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Lights, Fog Signals & Buoyage
South Cardinal Mark
Topmark
Two black cones
points downwards
Colour
Top Yellow
Bottom - Black
Light
Colour - White
Rhythm - Q(6)+LF or
VQ(6)+LF
N
W
Retroreflector
Yellow over Blue band
POINT
OF
INTEREST
E
S
Shape
Pillar or spar
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Lights, Fog Signals & Buoyage
West Cardinal Mark
Topmark
Two black cones
points together
Colour
Top - Yellow
Middle - Black
Bottom - Yellow
(W for wineglass)
N
W
POINT
OF
INTEREST
E
Retroreflector
Two Yellow bands
S
Light
Colour - White
Rhythm - Q(9) or VQ(9)
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Shape
Pillar or spar
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Lights, Fog Signals & Buoyage
To remember the light sequences think of a clock face, the long flash
immediately after the group of flashes of a South Cardinal mark
ensures that 6 flashes cannot be mistaken for 3 or 9.
Q or VQ
N
12
Q(9) or VQ(9)
Q(3) or VQ(3)
W
9
3
E
6
S
Q(6)+LFl. or VQ(6)+LFl.
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Lights, Fog Signals & Buoyage
Isolated Danger Marks
Colour - Black & Red
Shape - Pillar or spar
Topmark - Two black spheres
Retroreflector - Blue & Red band
Light - White, Group-flashing (2)
Use - Erected on or moored above
isolated dangers which have
navigable water all around them
Group-flashing light
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Fl(2)
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Lights, Fog Signals & Buoyage
Safe Water Mark
Colour - Red & White
Shape - Spherical, Pillar or spar
Topmark - One Red sphere
Retroreflector - Red & White bands or
Stripes
Light - White with the rhythms below
Use - To indicate navigable water all
round the mark. May be used as a
centreline, mid-channel or landfall
buoy or the best point to pass under a
bridgeIsophase
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Occulting
Long Flash every 10 secs
Morse Code A
Iso
Oc
LFl. 10s
Mo(A)21
Lights, Fog Signals & Buoyage
Special Marks
Colour - Yellow
Shape - Can be any shape
Topmark - Yellow cross
Retroreflector - Yellow band or cross
Light - Yellow, may have any rhythm not
used for white lights, some
examples below
Use - Indicates a special area or feature
the nature of which is apparent
from reference to the chart.
Yellow Flashing light
Group-flashing light
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Fl. Y
Fl(4)Y
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Lights, Fog Signals & Buoyage
IALA REGION B Lateral Marks
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Lights, Fog Signals & Buoyage
Characteristics of Lights


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There are four main characteristics to a light
RHYTHM
COLOUR
PERIOD
INTENSITY
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Lights, Fog Signals & Buoyage
Characteristics of Lights

RHYTHMS
F
Fl
Q
VQ
UQ
Oc
Iso
Alt
Mo
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Fixed
Flashing
Quick Flashing
Very Quick Flashing
Ultra Quick Flashing
Occulting
Isophase
Alternating
Morse Code
On all the time
< 50 flashes per min
50-80 flashes per min
80-160 flashes per min
> 160 flashes per min
More light than dark
Equal light and dark
Different colours
Flashes Morse Code
characters
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Lights, Fog Signals & Buoyage
Characteristics of Lights
COLOURS
W
White
R
Red
G
Green
Y
Yellow
Bu
Blue
Vi
Violet
If no colour is listed, the light is WHITE

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Lights, Fog Signals & Buoyage
Characteristics of Lights

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PERIOD
The period of a light is the time taken to
complete one full cycle of ON-and-OFF
changes.
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Lights, Fog Signals & Buoyage
Characteristics of Lights

PERIOD
The period of a light is the time taken to
complete one full cycle of ON-and-OFF
changes.
15 seconds
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Lights, Fog Signals & Buoyage
Characteristics of Lights

PERIOD
The period of a light is the time taken to
complete one full cycle of ON-and-OFF
changes.
15 seconds
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Fl (3) W 15s
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Lights, Fog Signals & Buoyage
Characteristics of Lights

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INTENSITY
A measure of the brightness or power of
the light.
The standard unit of measurement is
candelas.
However, on the majority of charts and
on all British Admiralty Charts, the
Nominal Range of a light is given.
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Lights, Fog Signals & Buoyage
Lights
The range of visibility is dependent on:



The intensity of the light
The prevailing visibility
The height of the light combined with the
height of eye of the observer.
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Lights, Fog Signals & Buoyage
Lights

The Intensity
–
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The brighter the light the further it can be seen.
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Lights, Fog Signals & Buoyage
Lights



The prevailing visibility
The range of a lights given on the chart or in
Admiralty List of Lights & Fog Signals(ALLFS) is
based on visibility being 10nm, this is referred to
as the Nominal range.
Visibility is rarely exactly 10nm so the ranges
given on Charts are a rough guide.
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Lights, Fog Signals & Buoyage
Lights


The height of the light combined with the
height of eye of the observer
The height of the light is also given on the chart or
in Admiralty List of Lights & Fog Signals(ALLFS).
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Lights, Fog Signals & Buoyage
Characteristics of Lights

Geographical Range
–
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Range of a light taking into account the height
of a light and the height of the observer
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Lights, Fog Signals & Buoyage
Characteristics of Lights

Geographical Range
–
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Range of a light taking into account the height
of a light and the height of the observer
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Lights, Fog Signals & Buoyage
Characteristics of Lights

Geographical Range
–
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Range of a light taking into account the height
of a light and the height of the observer.
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Lights, Fog Signals & Buoyage
Chart Symbology
FL (4) 20s 15m 12M
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Lights, Fog Signals & Buoyage
Chart Symbology
White light
Flashing in a
group of 4
FL (4) 20s 15m 12M
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Lights, Fog Signals & Buoyage
Chart Symbology
White light
Flashing in a
group of 4
FL (4) 20s 15m 12M
Period
4 flashes every
20 second
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Lights, Fog Signals & Buoyage
Chart Symbology
White light
Flashing in a
group of 4
Luminous range
12 Miles
FL (4) 20s 15m 12M
Period
4 flashes every
20 second
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Lights, Fog Signals & Buoyage
Chart Symbology
Elevation
15 metres above
M. H.W. S.
White light
Flashing in a
group of 4
Luminous range
12 Miles
FL (4) 20s 15m 12M
Period
4 flashes every
20 second
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Lights, Fog Signals & Buoyage
Characteristics of Lights

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CHART EXAMPLES
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Lights, Fog Signals & Buoyage
Characteristics of Lights


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CHART EXAMPLES
Fl (6) 30s
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Lights, Fog Signals & Buoyage
Characteristics of Lights


CHART EXAMPLES
Fl (6) 30s
–
A group of 6 white flashes every 30
seconds
30 seconds
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Lights, Fog Signals & Buoyage
Characteristics of Lights


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CHART EXAMPLES
Oc Y 12.5s
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Lights, Fog Signals & Buoyage
Characteristics of Lights


CHART EXAMPLES
Oc Y 12.5s
A Yellow light with one Occultation
every 12.5 seconds
12.5 seconds
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Lights, Fog Signals & Buoyage
Characteristics of Lights
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
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CHART EXAMPLES
FG
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Lights, Fog Signals & Buoyage
Characteristics of Lights


CHART EXAMPLES
FG
–
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A fixed green light
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Lights, Fog Signals & Buoyage
Characteristics of Lights


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CHART EXAMPLES
Iso R
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Lights, Fog Signals & Buoyage
Characteristics of Lights


CHART EXAMPLES
Iso R
–
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A red light with an equal duration of light
and darkness (Isophase)
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Lights, Fog Signals & Buoyage
Characteristics of Lights

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SECTOR LIGHTS
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Lights, Fog Signals & Buoyage
Characteristics of Lights

SECTOR LIGHTS
W
W
R
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Lights, Fog Signals & Buoyage
Fog Signals - LIMITATIONS





Heard at greatly varying distances
Affected by atmospheric conditions
Areas of inaudible sound
Fog signals may be unoperable at very short
notice
No accurate bearing or range information
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Lights, Fog Signals & Buoyage
Fog Signals

Abbreviations of fog signals found on
charts.

Dia
Siren
Reed
Explos
Bell
Gong
Whis
Horn







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Lights, Fog Signals & Buoyage
Summary
During this lesson we have covered the
following:
 The IALA buoyage system Region A.
 The general & local direction of buoyage.
 The characteristics of the different buoys
& lights used in this system.
 Abbreviations used on charts.
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Lights, Fog Signals & Buoyage
Objectives






You should now be able to:
Identify lights, fog signals, and IALA Buoyage
System (Region A) by day and night.
State the meaning of and identify general light
characteristics
Use ALLFS to a basic level
State the use and limitations of fog signals
Determine the meaning of and be able to pass
the safe side of IALA Buoyage (Region A)
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