of Lighthouse Authorities (IALA) was set up in 1979 to try to implement
universal system of buoyage world wide.
They were able to standardize everything except for the colors of
now have two IALA systems of buoyage.
uses red as the
color for port hand lateral marks.
uses red as the color for the starboard hand lateral marks.
the shape of the lateral marks is now the same world wide.
system's region B covers the Americas and areas of the world with
American influence such as Japan, Korea and the Philippines.
Region A covers
the rest of the world including Europe.
those which indicate the edge of a safe water channel.
The direction of buoyage
dictates how these are
The direction of buoyage
for all areas covered
by the IALA is always is always set in an upstream direction.
The direction is
always from the open sea into a harbor, estuary, bay or
Where there might be any
confusion, it will be
labeled on the appropriate chart and may be clarified with a cardinal
While the color of the
lateral marks may differ
across the two region the shape across both remains the same.
In both regions
port hand lateral marks are square (cans) or have a flat
marks are conical or triangular in shape and have a pointed
These lateral marks may
identification markings or names and distinctive light identification
These will indicated on
your marine chart.
Channel marks are a modification
of the standard lateral mark.
indicate a deep water
channel, suitable for heavy commercial traffic, with a secondary
suitable for shallower draught vessels to the side.
identified by a colored (red or
green) horizontal stripe.
All the other
buoys in the IALA system are
the same regardless of which region they are in.
Cardinal marks are
common to all buoyage
safe or deepest water side of a hazard.
The cardinal mark's name tells us which side the deepest water
For instance, one should always pass to the north of a North Cardinal
the deepest water lies in a 45 degrees quadrant to its north.
And stay to the east of the East Cardinal, south of the South Cardinal
of the West Cardinal.
Each mark is distinguished by the pattern of its horizontal yellow and
stripes, the arrangement of the top-marks and light signals.
There are several tricks you can use to
remember their characteristic
Perhaps the easiest to remember and the most important is the flashing
sequence, at night it will be the only one visible.
If you think of the diagram above in term of a clock face, north is at
o'clock, east at 3, south at 6 and west at 9.
The east cardinal (at
o'clock) flashes in groups of 3 separated with a blackout.
The southerly flashes in groups of 6, the west cardinal flashes in
groups of 9
while the northerly mark flashes continuously.
The speed of the flashing can be either (Q) quick, or (VQ) fast
will be indicated on your chart..
A (Q) flashing light has 50/60 flashes per minute while a (VQ) light
100/120 flashes per minute.
They all flash a white light.
day the cardinals can be identified by the arrangement of the black and
stripes and the black, cone shaped top-marks.
The arrangement of cones at the top is an indication of the black
stripes) position on the buoy.
The north cardinal has both cones pointing up and the black stripe is
The south cardinal has both cones pointing down and the black stripe is
The westerly mark has the cones pointing towards each other so it
have a narrow waist (waisted woman of the west has a black belt).
And there is a black stripe across the middle of the mark.
The east is opposite with the cones pointing away from each other and
stripes are at the top and bottom.
It is reasonable easy to remember the different cone shapes, however it
worth the effort to remember the color codes as these are much easier
distinguish at a distance.
marks Isolated danger marks are also common across both IALA
They indicate that there is a hazard directly below the mark, such as a
These are usually isolated dangers around which the water is safe to
They are easy to identify with their horizontal black and red stripes.
The top-marks are two black spheres one above the other.
They also have a white flashing light signal but in groups of 2, Fl(2)
black out between.
The safe water mark is
the only one
with vertical stripes.
The stripes are red and
white and it will
also have a red sphere as the top-mark.
They indicate that water
is safe for
navigation all around the mark.
They may be used to mark
or forks in a chanel.
When fitted with a light
it is usually white
however it may be isophase, occulting (rhythmic flashes of equal length
the period of light is longer than the dark) or flashing the Morse code
incorrectly identified mark is a hazard,
not an aid, to navigation" (Alton
also includes the
They are not so much
navigational aids as
indicators of special areas or objects mentioned on the charts or other
nautical and publications.
They can be of any shape
but are always
painted yellow and have a yellow light which will be distinctive from
lights in the area.
The top-mark is optional
but is usually a
Transit or Range
Range or transit markers
are often found on waterways
with particularly shallow patches and or with cross currents.
They do not come under the IALA system of buoyage and so can be
anything from a
couple of withes (simple poles) to a set of lights.
They are always found as a pair with one higher than the other.
They are there to help you to keep to the center line of a channel.
The back marker is always higher than the front one.
The idea is keep the two in line while in the channel.
To keep the pair in line always steer towards the lower front marker.
You also need to watch for the normal buoyage marker which signals the
that stretch of the channel where you will need to turn.
Sector Lights as with
markers are designed to help keep you in a safe navigational area.
The light emitted from a single position will show up as either red,
green depending on the angle.
Every light is set up specifically for that particular area but its
will be clearly marked on the chart.
Depending on the color of the light that he can see the navigator can
which sector he is in.
Like the range markers they indicate the safe area of a channel or
waterway but as with range markers they cannot indicate where the
So, you also need to watch out for other buoyage marks and refer to
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