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Navigation—buoys, marks and beacons

Traffic lights and signs guide drivers on the roads. Buoys and beacons and navigation lights do the same on the water.

IALA buoyage system

In Queensland, the system of buoys, beacons, marks and lights used is compliant with the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) Buoyage System ‘A’.

Each type of mark has its own colour, shape, top mark and light combination.

To navigate safely, you need to know each mark and its meaning.

Lateral marks

Lateral marks show the port (left) and starboard (right) sides of navigable waters or channels. 

A port mark is red 
with a can-like shape.

Example of a port lateral mark in daylight
At night, a port buoy shows
a red flashing light (when lit).

Example of a port lateral mark at night


A starboard mark is green
with a cone-like shape.

example of a starboard lateral mark in daylight
At night, a starboard buoy shows
a green light (when lit).

example of a starboard lateral mark at night

When a port and starboard lateral mark are opposite each other, travel between them. Sometimes they are not in pairs though. When there is a single lateral mark, the safe side to pass depends on the direction of travel (or buoyage).The direction of buoyage is shown on charts by the symbol:

Graphic of a directional arrow that may be found on a chart

When travelling upstream or away from the sea:

  • keep port (red) marks on your port-hand side (left)
  • keep starboard (green) marks on your starboard-hand side (right).

When travelling downstream or towards the sea:

  • keep port (red) marks on your starboard-hand side (right)
  • keep starboard (green) marks on your port-hand side (left).

Cardinal mark features

Cardinal marks show where the deepest and safest water is by using a compass. They can mark:

  • where to find the deepest water in an area
  • the safe side to pass a danger
  • a feature in a channel (for example, a bend, junction or the end of a shoal).

Cardinal marks have black and yellow bands with black double cones on top showing the different compass direction that identifies the safest and deepest water to travel in.

At night, each type of cardinal mark has a flashing white light with different groupings of flashes (continuous, or groups of 3, 6 or 9).

To remember each type, think of a compass face with the numbers of a clock marked on it beside each direction (North, East, South and West).

North cardinal mark

North cardinal marks show there is safe water to the North of the mark.

The top cones point up or North.

example of a north cardinal mark in daylight
At night, the white light
flashes quickly or very quickly
and continuously.

example of a north cardinal mark at night

East cardinal mark

East cardinal marks show there is safe water to the East of the mark.

The top cones are in the shape of
an egg. To remember this, think of
‘e’ for egg and for East.

example of an east cardinal mark in daylight
At night, the white light flashes
quickly or very quickly 3 times
every 5 or 10 seconds.

example of an east cardinal mark at night

South cardinal mark

South cardinal marks show there is safe water to the South of the mark.

The top cones point down or South.

example of a south cardinal mark in daylight
At night, the white light flashes
quickly or very quickly 6 times
followed by a long flash every
10 or 15 seconds.

example of a south cardinal mark at night

West cardinal mark

West cardinal marks show there is safe water to the West of the mark.

The top cones make the shape of
a wine glass. To remember this,
think of ‘w’ for wine glass and for West.

example of a west cardinal mark in daylight
At night, the white light
flashes quickly or very
quickly 9 times every
10 or 15 seconds.

example of a west cardinal mark at night

Isolated danger marks

Isolated danger marks show where there is an isolated danger that has navigable water all round it (for example, an isolated shoal, rock or wreck) – but don’t pass too close.

Isolated danger marks are black with 1 or more red horizontal bands and 2 spheres as the top mark.

At night, the white light flashes in groups of 2.

To remember isolated danger marks, think of 2 flashes of light with 2 spheres as the top marks.

example of an isolated danger mark in daylight
example of an isolated danger mark at night

Safe water marks

Safe water marks show that there is navigable water all around the mark. For example, fairway, mid-channel or landfall mark.

Safe water marks have red and white vertical stripes with a single red sphere as the top mark.

At night, a single white light shows 1 long flash every 10 seconds.

To remember safe water marks, think of 1 light with 1 long flash and 1 sphere for the top mark.

Image of a safe water mark during daylight
Image of a safe water mark at night

Special mark features

Special marks show a special area or feature. For example, to show that a channel divides or to mark cables or pipelines.

They can also mark a channel within a channel. For example, a channel for deep draught ships in a wide river or bay where the limits of the channel for normal navigation are marked by red and green lateral buoys or beacons.

The direction to travel around a special mark is usually referred to or shown on charts.

Special marks are yellow and sometimes have a yellow X as the top mark.

At night, the flashing light is yellow.

example of a special mark in daylight
example of a special mark at night

Emergency wreck marking buoy

Emergency wreck marking buoys are used to identify new dangers or wrecks.

They have blue and yellow vertical stripes and are a pillar or spar shape with a yellow cross as the top mark.

At night, the flashing light alternates between 1 second of blue light and 1 second of yellow light, with 0.5 seconds of darkness in between.

New dangers mark
 

Other navigational aids

There are some other aids to navigation that you need to be aware of.

Leads

Leading lights/beacons usually display a triangle shape. The front lead has its apex pointing up and the rear or back lead has its apex pointing down.

When the leads are in line, you are travelling in the middle of the channel. Where leads are used to mark the middle of larger shipping channels small vessels should travel on the starboard side of the channel to keep clear of large ships. This is especially important at night.

Fixed white day lights are sometimes used to mark the leads. At night, major leads are usually lit with blue lights.

Blue middle channel mark

Blue middle channel marks are fixed blue lights that mark the middle of the channel for vessels passing under a bridge.

On a chart, they are normally shown as a star with a flash symbol.

Directional and sector lights

Directional and sector lights have a similar purpose to leading lights at channel entrances and inshore waters.

Directional lights can be used as steering marks and sector lights display a light of different colours (usually green, white and red).

Port traffic signal lights

Port traffic signal lights have 3 red vertical flashing lights that are remotely controlled by Maritime Safety Queensland’s vessel traffic services to tell others in the area that large commercial ships are moving in the port, harbour, marina or other confined waterway.

Vessels must not enter or depart the port or harbour area when the port traffic signal lights are flashing.

Further information

Last updated
31 August 2016