IALA Buoyage
Road signs on the water

Buoys, Beacons and Marks

The IALA Buoyage System is a worldwide standard sea mark system used in navigation to mark the edge channels. These road signs on the water are made up of five buoy types- cardinal, lateral,isolated danger, special and safe water marks. These buoys and marks indicate where safe water lies. Refer to to a local chart to identify where potential hazards may be. Attending a boat licence course while help you to learn how to interpret these signs.

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  • Lateral Channel Marks
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    These show well-established channels and indicate port (left) and starboard (right) sides of the channels. Port marks are a red can shape. At night, a red flashing light may be shown. Starboard marks are a green conical shape. At night a green flashing light maybe shown.

  • Cardinal Marks
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    Coloured yellow and black each indicates where there is deep water close to a danger and they show this relative to the compass. NORTH - white light continuous quick flashing light. Pass to North. SOUTH - white light 6 quick flashes + 1 long flash. Pass to South. EAST - white light 3 quick flashes. Pass to East. WEST - white light 9 quick flashes. Pass to West.

  • Isolated Danger Marks
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    Indicates an isolated danger, such as a submerged rock. It tells you not to pass too close. Coloured black with one or more horizontal red bands. If lit at night it shows a group of two white flashes. The top mark has two round spheres.

  • Special Marks
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    Indicates a special area which should be kept clear of. Coloured yellow, if lit at night it shows a flashing yellow light. The top mark is a single yellow cross. Check your chart to find out what is special in the area you are boating in.

  • Safe Water Marks
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    Safe water marks - are red and white striped beacon or buoy, often an isophase or occulting white light. It is used to signify that you [are in safe waters. This sea mark implies that open, deep and safe water lies ahead, though it is sometimes used to indicate the start and end of a buoyed section of a continuous narrow channel or a line of these marks can be used to mark a safe route through shallow areas. In Sydney Harbour it is used as a 'centre line of the channel' and vessels are required to leave it to port when navigating past Bradley's Head in either direction. Pass this mark to port when traveling up (coming in from sea) or, down stream (going out to sea)


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