In Europe, Africa, India and Australia and in other countries that were or still are part of the British sphere of influence we use the the IALA (International Association of Light House Authorities) 'A' system, whereas North & South America, the Caribbean, Japan and the Philipinnes use the 'B' system.

The difference being that with the 'A' system when following the direction of the buoyage coming in from the sea we leave red buoys to port and green to starboard when going back out to sea we leave red buoys to starboard and green to port.  The IALA 'B' system is exactly the other way around, which when I visited the Caribbean a few years ago I found very confusing and on a few occasions almost went the wrong side of buoys when entering a harbour for the first time. Red and Green buoys are known as 'Lateral Marks', for more information read my article on Pilotage.

Cardinal Marks are fortunately exactly the same in both systems. It is very easy for me when giving instruction to clients in the Algarve to forget to explain Cardinal Marks, why, well simply because there aren't any in the Algarve, and as I spend most of my time sailing or motor cruising in the Algarve, I don't see them very often.

As far as I know the nearest to us are two just outside Cascais marina and two near Chipiona close to the entrance to the Guadalquiver river that leads up to Seville. It is an important part of the RYA syllabus and vital that one can instantly understand exactly why they are there and know what is required of us when navigating near them; they can either be a post or a buoy. 

The diagram above may look rather confusing at first, but it is in fact very simple.

1. Starting with the one at the top, you will see that the two black triangles are both pointing up, as north is generally up on a map or a chart we know that this is a North Cardinal mark and we should go to the north of it.

2. Now working clockwise look at the one to the right (east) of the diagram. This has one black triangle pointing up and the other down, this one is an East Cardinal mark and we should go to the east of it. I remember this one because the shape created by the two triangles is almost egg shaped, egg begins with an E and East also begins with an E.

3. Continuing clockwise the one at the bottom has two black triangles pointing down, down is normally associated with south so this one must be a South Cardinal and we should go to the south of it.

4. Again moving clockwise, the mark on the left of the diagram has one black triangle pointing down and the other up with their points almost touching. This hour glass shape is what women strive for, 'women' begins with a 'W' so does west and so this one must be a West Cardinal and we should go to the south of it.

When you are about a mile or more away from a Cardinal Buoy it can be difficult to see which way the triangles are pointing even with binoculars.  The buoys are therefore painted yellow and black in a certain way to help us identify them from a distance.  You will notice that the black stripes are positioned so that they are in the same place as where the triangles are pointing.  A North Cardinal therefore has a wide black stripe at the top, an East Cardinal has one at the top and another at the bottom. A South Cardinal has a wide black stripe at the bottom and a West Cardinal has a black stripe in the middle.

Simple!  But how can you see them in the dark, also simple!  If they are lit (some in very small harbours where you would not be navigating in the dark do not have lights) they have lights which follow a very simple pattern.  A North Cardinal will be flashing continuously either 'Q' (quick) or 'VQ' (very quick).  Now again moving clock wise an East Cardinal which I think you will agree is in the same position as 3 on a clock, will flash 3 times, a South Cardinal which is in the same position as 6 on a clock will flash 6 times but with one long flash after the 6 flashes, and a West Cardinal will flash, yes you have got it!, 9 times because it is in the same position as 9 on a clock.

You will see on a chart that the duration of the flashes is also shown, this is only important really if you are either uncertain of your position or if there are two cardinal buoys of the same type close to each other, then by timing their duration you will know which is which.  Remember the duration of flashes on a buoy is from the start of the pattern to the start again of the pattern, so it includes the part when there is nothing happening.

Finally – take them seriously. I was recently going past Europa Point (Gibraltar) in a motor cruiser two days after an oil tanker had gone aground there. There was an East, a South and a West Cardinal Buoy to keep vessels away from the wreck, I wanted to get close enough to get a really good photograph and it seemed to me that the Cardinal Buoys had been put unnecessarily far away, and I was very tempted to ignore them and go in a bit closer to get a better photograph. I resisted the temptation because I realised that as the tanker had clearly split in half there might be another part of the ship under the water that I could not see.  I was in a Sunseeker probably worth almost a million euros and to hit something under the water of which I had been given clear warning would have been more than just a little embarrassing!  Plus as a result of an enquiry into the incident I would have been disqualified as a Yachtmaster and never would have worked again as an Examiner or an Instructor.  To see the photograph that I took click here and scroll down.