Don’t be blasé about buoyage

It never hurts to refresh your memory...

It never hurts to refresh your memory...

Knowing your buoyage is like knowing your traffic signs on the road. But just as the less common signs in the Highway Code have a tendency to fade from memory over time, do you become blasé about what you’re seeing on the water? There’s a big difference between seeing, understanding and interpreting for a safe passage explains Rachel Andrews, RYA Chief Instructor, Motor Cruising and Power.

It is a bit of an understatement to say that an understanding of buoyage is pretty important when you are heading out to sea. Even if you are an experienced mariner, it never hurts to refresh your memory so here is a brief overview of what buoys to look for and what they mean (this is by no means and exhaustive list of all the buoyage you may see out on the water)

1) Port and starboard marks

These are the most common marks. They flash red or green to any rhythm (apart from group flashing 2+1. This sequence is reserved for preferred channel marks. These may be seen where a channel divides) - the light sequence will be marked on the chart for a specific buoy - to mark the outer edge of a channel.

Lateral marks are laid in the direction of the flood tide.

In International Association of Lighthouse Authorities (IALA) region A, which incorporates much of the world, including the UK and Europe, red cans mark the port side of the channel, and green cones mark the starboard side.

Did you know that in North or South America, or certain parts of South-East Asia although the shapes of the buoys are consistent, the colour of the lateral marks are the opposite?

These areas are part of IALA (B) - just to keep you on your toes! This is something you will need to explore further if you are planning on venturing further afield.

Tip: If you are in any doubt about the direction of buoyage, then check on the chart for this arrow.

2) Cardinal Marks

These are used to indicate the direction of the safest navigable water from a mark. For example, if you see a South Cardinal ahead, you should stay to the south.

The light sequences can be either quick (Q) or very quick (VQ), which allows for two similar nearby marks to be uniquely identified by their lights.

Cardinal marks are often seen off headlands, shoals or potentially a change in the direction of buoyage. They are laid to indicate the area of safe water.

3) Safe Water Mark

Sometimes called a ‘Fairway Buoy’ or ‘Sea Buoy’, they are striped vertically red and white, have a single ball on top and flash a single long white flash every 10 seconds.

These buoys are usually set in safe, deep water at the seaward end of fairways, or harbour approach channels. They have unobstructed water on all sides.

Traditionally, they are the point of departure or, when arriving, the waypoints to aim for, and mark the transition from open water navigation to pilotage.

Picture courtesy of Paul Glatzel

4) Isolated Danger Mark

These marks are used to mark a relatively small hazard in the middle of an area of open water. They can be passed on either side although you should exercise caution when approaching.

They can be buoys, beacons, or even concrete pillars but they are always painted with red and black horizontal stripes with two black balls on top.

If they are lit it will be with a white light flashing in groups of two.

5) Special Marks

These marks have no navigational significance but mark special areas or features such as racecourse areas, to define swimming or water-skiing zones, anchoring, fish farming, firing ranges and jetties, for example.

They are not used to mark a hazard to navigation.

Special marks can be all sorts of shapes, but are always yellow and often have a cross as a top mark. If they are lit, it will be with a yellow light.

Find out more

The importance of the understanding and interpreting of buoys in navigation cannot be underestimated. For further learning or knowledge refreshment, whatever your level of experience visit