Emergency wreck marking buoy

IALA has introduced on trial basis.

For temporary response.
Typically to be used for first 24-72 hrs.
Deployment to be promulgated through usual maritime safety information system.
Designed to provide a prominent aid to navigation.
To be placed as close of wreck as possible.

It will maintain a position until:

The wreck is well known and has been promulgated in nautical publications eg
notices to mariners.
The wreck is fully surveyed and exact details such as position and least depth above
the wreck is known.
A permanent form of marking of the wreck has been carried out.

Characteristics:

Shape: Pillar or spar buoy, size dependent on location.

Color: Equal number and dimensions of blue and yellow vertical stripes.

Light:

Altering blue and yellow flashing light.

Nominal range: 4 nm, may be altered depending on local condition.
Blue and yellow 1s flashes altered at interval of 0.5s.
If multiple buoys deployed, their lights will be synchronized.

Racon: May be fitted with Racon-D and/or AIS transponder.

Topmark: If fitted, straight yellow cross.

 Lights and buoys
 

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Aids to navigation
Aids to navigation are special structures like lighthouses, lightships, beacons,
buoys, etc that are used to enhance safety by providing more opportunities to
obtain LOPs.

These lights and marks are prescribed across the world by the International
Association of Lighthouse Authorities (IALA). In 1977 this IALA endorsed two
maritime buoyage systems putting an end to the 30 odd systems existing at
that time. Region A - IALA A covers all of Europe and most of the rest of the
world, whereas region B - IALA B covers only the Americas, Japan, the
Philippines and Korea. Fortunately, the differences between these two systems
are few. The most striking difference is the direction of buoyage.
All marks within the IALA system are distinguished by:

Shape
Colour
Topmark
Light

Light identification
During daytime, the identification of aids to navigation is accomplished by
observing: location, shape, colour scheme, auxiliary features (sound
signals, RACON , RC , etc) or markings (name, number, etc).

During the night, we use the features of the aid to navigation's light to both
identify it and ascertain its purpose. There are three features to describe the
light:

Colour: Either white, red, green or yellow. If no colour is stated in the

chart, default is white.
 Period: The time in seconds needed for one complete cycle of changes.
   The arrow indicates the 10 second period of this flashing
light “Fl(3) 10s”.
Phase characteristic: The particular pattern of changes within one
complete cycle (hence, within one period). Below are the most common types:

Fixed   F
   This light shines with an unblinking and steady
intensity and is always on. In this example a yellow fixed light is shown.
Flashing   Fl:
   The duration of the light is always less than the
duration of the darkness. The frequency does not exceed 30 times per
minute.
Quick Flashing   Q:
   Again, the duration of quick flash is less than the
darkness. The frequency is at least 60 times per minute.
Very Quick Flashing   VQ:
   Also here, the duration of very quick flash is less
than the darkness. The frequency is at least 100 times per minute.
Interrupted Quick Flashing   IQ:
   Like Quick Flashing with one moment of darkness
in one period.
Isophase   Iso:
   This Light has equal duration between light and
darkness. A period consists of both a light and a dark interval. Also called
Equal Interval (E Int).
Group Flashing   Gp Fl(x+x):
   This is actually a combination of two patterns in
one period. In this example the first 2 flashes followed by the pattern of 3
flashes result in: Gp Fl(2+3).
Occulting   Occ:
   Occulting is the opposite of flashing, the light is
more on then off.
Alternating   AL:
   An alternating light changes colour. This special
purpose light is typically used for special applications requiring the
exercise of great caution. In this example ALT.WG is shown, alternating
between green and white.
Morse U   Mo (U):
   This light shows two flashes and a longflash, which
is equivalent to the letter “U” in Morse code.
Long-Flashing   LFl:
   This light has one long flash in a period. A long
flash is at least 2 seconds long.
Let's look at some examples using colour, period and phase characteristics. The
arrows mark the periods:

  Fl (4) 8s
  Oc (2+3) 10s
  Iso G 4s

All lighted aids to navigation are either major or minor lights, where major
lights are used for key navigational points along sea-coasts, channels and
harbour and river entrances. These lights are normally placed in lightships,
lighthouses and other permanently installed structures, providing both high
intensity and high reliability of the lights. Major lights are then subdivided in
primary lights (very strong, long range lights used for the purpose of making
landfalls or coastal passages) and secondary lights (shorter range lights found
for example at harbour and river entrances). Important details of (especially)
primary lights can be found in a reference called the Light List where
information (about pedestals etc.) can be found which is not included in the
chart.
Minor lights on the other hand are likely to be found within harbours, along
channels and rivers. These have a low to moderate intensity and sometimes
mark isolated dangers.

Six types of navigation buoys:

Lateral
Cardinal
Isolated danger
Safe water
New wreck
Special

Lateral buoys and marks

The location of lateral buoys defines the borders of channels and indicates the
direction. Under IALA A red buoys mark the port side of the channel when
returning from sea, whereas under IALA B green buoys mark the port side of
the channel when sailing towards land. Red buoys have even numbers and red
lights; green buoys have odd numbers and green lights. Lateral lights can have
any calm phase characteristic except FL (2+1).
 

Generally, when two channels meet, one will be designated the

preferred channel (i.e. most important channel). The buoy depicted on the right
indicates the preferred channel to starboard under IALA A. The light phase
characteristic is R FL (2+1):
 

The buoy depicted on the left indicates the preferred channel to port
under IALA A. These buoys are marked with the names and numbers of both
channels. The light phase characteristic is G FL (2+1):

For an example of lateral buoys used to mark a (preferred) channel, see

direction of buoyage below.

Cardinal buoys
The four cardinal buoys indicate the safe side of a danger with an approximate
bearing. For example, the West cardinal buoy has safe water on its West and
the danger on its East side. Notice the “clockwise” resemblance of the light
phase characteristics. The top marks consist of two black triangles placed in
accordance with the black/yellow scheme of the buoy. When a new obstacle
(not yet shown on charts) needs to be marked, two cardinal buoys - for
instance a South buoy and an East buoy - will be used to indicate this
“uncharted” danger. The cardinal system is identical in both the IALA A and
IALA B buoyage systems.
Marks indicating isolated dangers

This type of buoy indicates the position of an isolated danger,

contrary to cardinal buoys which indicate a direction away from the danger.
Body: black with red horizontal band(s); Topmark: 2 black spheres. The light
(when present) consists of a white flash: Fl(2).
 Marks indicating safe water

Notice that whereas most horizontal

striping spells “danger”, this safe water buoy is vertically striped. These marks
are for example seaward of all other buoys (lateral and cardinal) and can be
used to make landfall. Body: red and white vertical stripes; Topmark (if any):
single red sphere. Lights are typically calm and white: Morse A, Iso, Occ or LFl
10s.

Marks for new wrecks

After the sinking of the “Tricolor” in the Pas de Calais (Dover Straits) in 2002,
several other vessels hit the wreck despite standard radio warnings, three guard
ships and a lighted buoy. This incident spawned a new type of buoy, the
emergency wreck marking buoy, which is placed as close as possible to a
new dangerous wreck.

The emergency wreck marking buoy will remain in position until: a) the wreck is
well known and has been promulgated in nautical publications; b) the wreck has
been fully surveyed and exact details such as position and least depth above the
wreck are known; and c) a permanent form of marking of the wreck has been
carried out.

The buoy has the following characteristics:

 A pillar or spar buoy, with size dependant on location.

 Coloured in equal number and dimensions of blue and yellow vertical
stripes (minimum of 4 stripes and maximum of 8 stripes).
 Fitted with an alternating blue and yellow flashing light with a nominal
range of 4 nautical miles where the blue and yellow 1 second flashes are
 alternated with an interval of 0.5 seconds.
B1.0s + 0.5s + Y1.0s + 0.5s = 3.0s  
 If multiple buoys are deployed then the lights will be synchronized.
 A racon Morse Code “D” and/or AIS transponder can be used.
 The top mark, if fitted, is a standing/upright yellow cross .

It is important to realize - especially for the colour-blind - that this new buoy
breaches the useful and crucial convention: vertical stripes equal safety,
horizontal stripes equal danger.

Special buoys and marks

I have saved these buoys for last since they lack an actual navigational goal.
Most of the time these yellow buoys indicate pipelines or areas used for special
purposes.
I have drawn the five official IALA shapes, from left to right: conical, spar,
cylindrical, pillar and spherical.

Chart symbols
The seafaring nations of the world - members of the International Hydrographic
Organization - agreed in 1982 on an universal set of chart symbols,
abbreviations, colours, etc to be used in the nautical chart, in order to obtain
uniformity.

On regular charts a white, red, yellow or green lights will be indicated by ,

and on GPS displays and modern multi-coloured charts in specific colours:
, with the yellow coloured lobe indicating a white light.
The precise position of a chart symbol is its center, or is indicated with a line
and circle , the “position circle”.

Two distinct types of sea mark are drawn differently in the chart:

beacons - fixed to the seabed; drawn upright;

 buoys - consisting of a floating object that is usually anchored to a
specific location on the sea floor; drawn at an oblique angle and with oblique
numbering, descriptions of colours and light characteristics.

Major floating light (light-vessel, major light-float,

LANBY)

Light-vessel

Major light; minor light

Green or black buoys (symbols filled black): G =

Green ; B = Black
Green or black beacon (symbol filled black). Note
the upright G, instead of an oblique G
Single coloured buoys other than green and black:
Y = Yellow ; R = Red
Coloured beacon other than green and black, the
symbol is again filled black so only the shape of the
topmark is of navigational significance.

Multiple colours in horizontal bands, the colour

sequence is from top to bottom

Multiple colours in vertical or diagonal stripes, the

darker colour is given first. W = White

Spar buoy (here a safe water mark)

Lighted marks on multi-coloured charts, GPS

displays and chart plotters.

Lighted red beacon on standard charts.

Red beacon and green buoy with topmark, colour,

radar reflector and designation. Red buoys and
marks are given even numbers, green buoys and
marks are given odd numbers.
Wave-actuated bell buoy to the left, and to the right
a Light buoy, with a horn giving a single blast every
15 seconds, in conjunction with a wave-actuated
whistle. Other sounds include “Gong”, “Siren”,
“Diaphone” (Dia).
The fog signal symbol may be omitted when a
description of the signal is given.
 Leading beacons - Leading line (firm line is the track
to be followed)
Leading lights (≠ : any two objects in line under each
other). Bearing given in degrees and minutes. The
lights are synchronized. The red light has a shorter
nominal range (the distance from which the light
can be seen): 10 nautical miles.

All-round light with obscured sector

Sector light on multi-coloured charts.

The elevation is 21 metres (height of the light
structure above chart datum).
The nominal range of the white light is 18 nautical
miles. The range of the green and red light is 12
nautical miles.

Main light visible all-round with red subsidiary light

seen over danger. The fixed red light has an
elevation of 55 metres and a nominal range of 12
nautical miles. The flashing light is white, with three
flashes in a period of 10 seconds. The elevation is
higher than the red light: 62 metres and the range
of the white light is 25 nautical miles.
Symbol showing direction of buoyage (where not
obvious)
Symbol showing direction of buoyage (where not
obvious), on multi-coloured charts (red and green
circles coloured as appropriate), here IALA A
Full example of a light description in the chart:

Fl(3)WRG.15s21m15-11M
Class of light: group flashing repeating a group of three flashes;
Colours: white, red, green, exhibiting the different colours in defined sectors;
Period: the time taken to exhibit one full sequence of 3 flashes and eclipses:
15 seconds;
Elevation of light : 21 metres;
Nominal range(s): white 15 M, green 11 M, red between 15 and 11 M, where
“M” stands for nautical miles.

Lateral Marks - direction of buoyage

 Lateral marks are generally for well-defined channels and there are two
international Buoyage Regions - A and B - where these Lateral marks differ.
Where in force, the IALA System applies to all fixed and floating marks except
landfall lights, leading lights and marks, sectored lights and major floating
lights.

The standard buoy shapes are cylindrical (can) , conical , spherical , pillar
and spar , but variations may occur, for example: minor light-floats . In
the illustrations below, only the standard buoy shapes are used.
In the case of fixed beacons - lit or unlit - only the shape of the topmark is
of navigational significance.

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Visibility of lights
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It is important to know at what distance we may (begin to) see a certain light,
and when we can expect to lose sight of it, especially when making landfall.
Several practical ranges are used to the describe the visibility of lights in
navigation:

The meteorological range is based on the current atmospheric

conditions. The table below shows that the atmosphere immensely influences
the visibility of light travelling through it.

Meteorological Optical Range Table

Code No. Weather Distance (m) Code No. Weather Distance (nm)
 0 Dense fog Less than 50  5 Haze 1.0 - 2.0
 1 Thick fog 50 - 200  6 Light haze 2.0 - 5.5
   
 2 Moderate 200 - 500  7 Clear 5.5 - 11.0
 3 Light fog 500 - 1000  8 Very clear 11.0 - 27.0
 4 Thin fog 1000 - 2000  9 Exceptionally clear Over 27.0

 The geographic range is based on the elevation of the light. A higher

light means that its horizon is farther away, see distance of horizon.
 Moreover, if the observer's height of eye is higher than sea level the light can
been seen beyond its geographic range, the dipping range. However, on sailing
yachts this potential is limited.

 The nominal range of a light is based on its candlepower, and is

typically the range mentioned in the chart. The nominal range is the maximum
distance at which a light can be seen in weather conditions where visibility is 10
nm.

So, a minor light - perched on a 70m high cliff - with a geographic range of 20
nm will not be detectable by the human eye at a distance of 6 nm

1. if the nominal range is just 5 nm.

2. if the meteorological range is just 5 nm due to a light haze.

Because of the limiting factor of the geographic range, most major lights will
never be seen from a sailing yacht 20 nm away. Yet, it is sometimes possible to
take a bearing on the loom of the light: its reflection against the clouds.

Different coloured lights with equal candlepower have different ranges. White
light is the most visible followed by yellow, green and then red. Therefore, at
extreme ranges an “AL WG” can resemble a “Fl W”.

The range of a lit buoy is never indicated - with the exception of a LANBY - but
on a clear night the maximum range is 3 nm, yet often considerably less.
There are 2 visual clues to determine your distance from a buoy: at about 0.5
nm, the light will rise up from the horizon, and at about 200m, the light will
reflect in the surface.

Buoy at Buoy at Buoy at

less less less
than 3 than than
nm 0.5 nm 200m

Glossary
 Navigation aid: An onboard instrument, device, chart, method, etc.,
intended to assist in the navigation.
 Aid to navigation: A device or structure external to the ship, designed
to assist in determination of position, to define a safe course, or to warn of
dangers or obstructions.
 Mark, seamark, navigation mark: An artificial or natural object of
easily recognizable shape or colour, or both, situated in such a position that it
may be identified on a chart. A fixed artificial navigation mark is often called a
Beacon.
 Light characteristics: The sequence and length of light and dark periods
and the colour or colours by which a navigational light is identified.
 Topmark: One of more objects of characteristic shape placed on top of a
buoy or beacon to aid in its identification.
 Lateral Mark: An aid to navigation intended to mark the sides of a
channel or waterway.
 Cardinal Marks: An IALA aid to navigation intended to show the location
of a danger to navigation based on its position relative to the danger using the
“cardinal point”: north, east, south, west.
 Isolated danger Marks: An IALA aid to navigation marking a danger
with clear water all around it; it has a double ball topmark and is black with at
least one red band. If lighted its characteristic is Fl(2).
 Sector light: A light having sectors of different colours or the same
colour in specific sectors separated by dark sectors.
 Light sector: As defined by bearings from seaward, the sector in which a
navigational light is visible or in which it has a distinctive colour difference from
that of adjoining sectors, or in which it is obscured.
 Lighthouse: A distinctive structure exhibiting a major navigation light.
 Light List: A publication giving detailed information regarding lighted
navigational aids and fog signals.
 Landfall: The first sighting (even by radar) of land when approached
from seaward.
 Range: Two or more objects in line. Such objects are said to be in range.
An observer having them in range is said to be on the range. Two beacons are
frequently located for the specific purpose of forming a range to indicate a safe
route or the centerline of a channel.
 Leading line: On a nautical chart, a straight line, drawn through leading
marks. A ship moving along such line will clear certain dangers or remain in the
best channel.
 Range lights, leading lights: Two or more lights at different elevations
so situated to form a range (leading line) when brought into transit. The one
nearest to the observer is the from light and the one farthest from the observer
is the rear light. The front light is at a lower elevation than the rear light.
 Lights in line: Two or more lights so situated that when observed in
transit they define a position: the limit of an area, an alignment used for
anchoring, etc. Not to be confused with range lights, which mark a direction to
be followed.
 Light-float : A buoy having a boat-shaped body. Light-floats are nearly
always unmanned and are used instead of smaller lighted buoys in waters
where strong currents are experienced.
 Primary (sea-coast) light: A light established for purpose of making
landfall or coastwise past from headland to headland.
 Secondary light: A major light, other than a primary (sea-coast) light,
established at harbour entrances and other locations where high intensity and
reliability are required.
 Major light: A light of high intensity and reliability exhibited from a fixed
structure (lighthouse) or on marine site (except range lights). Major lights
include primary sea-coast and secondary lights.
 Minor light: An automatic unmanned light on a fixed structure usually
showing low to moderate intensity. Minor lights are established in harbours,
along channels, along rivers, and in isolated dangers.
 Visual range: The extreme distance at which an object of light can be
seen.
 Geographic range: The extreme distance limited by the curvature of the
earth and both the heights of the object and the observer.
 Bobbing a light: Quickly lowering the height of eye and raising it again
when a navigational light is first sighted to determine if the observer is at the
geographic range of the light.
 Luminous range: The extreme distance limited only by the intensity of
the light, clearness of the atmosphere and the sensitiveness of the observer's
eye.
 Luminous range diagram: A diagram used to convert the nominal
range of a light to its luminous range under existing conditions.
 Charted or Nominal Range: The nominal range is indicated in the chart
next to the light or can be found in the Light List. This is the maximum distance
at which a light may be seen at night based upon intensity and 10 nautical miles
of visibility.
 Meteorological Range: The nominal range is indicated in the chart next
to the light or can be found in the Light List. This is the maximum distance at
which a light may be seen at night based upon intensity and 10 nautical miles of
visibility.

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