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In the ninth instalment of our Sea Signs series William decipher buoys, the signposts of the sea.

9. BUOYS.jpg


Buoys are not just for sailors; they are invaluable to anyone having along the coast. Of all the elements explored in this series, buoys are the only one actively telling you something; go this way, not that way; stay to the north, or go south; this is safe water, and it’s dangerous over there. Through shapes, colours and lights, buoys are our Signposts of the Sea and in this piece we’re going to explore how to read them. A good starting point is the ‘Safe Water’ buoy with red and white vertical stripes and a single red ball on top. This shouldn’t to be confused with the similar looking ‘Isolated Danger’ buoy, with red and black horizontal stripes and two black balls. The mnemonic that helps distinguish them is that black of the Isolated Danger is a darkness to be avoided, whereas if you stay in the white light of the Safe Water Mark you’ll be all right.


When I worked on the ‘Dover Sea Safari’ we would take people on trips to a seal colony in the River Stour, near Sandwich. To get there we had to navigate a channel through the silty Sandwich Bay, invisible except for a set of carefully laid red and green buoys called Lateral Marks. The strategy is to keep the red ‘cans’ on your left and green ‘cones’ on your right when travelling towards land [the opposite applies when heading back out to sea]. My favourite part was when we reached the first port marker and made an astonishingly steep left turn, catching our guests unaware after a long period of cruising in a straight line. The dramatic shift in gravity, rush of air and spray of water always resulted in the same buzz of excitement from our passengers, with hysterical shrieks of delight. Speed and saltwater certainly make an energising mix.


Although not designed to do so, buoys are fantastic at showing what way the currents are flowing. Just like how water creates turbulence downstream of structures like pier legs, the same applies to buoys held in place by a rope to the seabed. If you look closely, even on the smallest buoys, you’ll notice a ‘bow wave’ against the upstream side of the buoy, and whitewater immediately downstream. While pondering this use of buoys, my mad inventors mind rushed into overdrive and I dreamt up a new buoy, the Current Buoy [patent pending]. The concept is that a 360-degree swivelling rudder faces into the current and is connected to a bar running through the buoy with an arrow at the top, thus pointing which way the water is flowing. I originally imagined it for beaches with strong tidal currents to aid recreational sea users, but it can also be used to indicate rips on surf beaches, and even help boaters quickly spot the currents in tricky stretches of water.


One of the most common buoys is yellow and black with two cones on top. To the casual observer this may look like one design, but in fact it has four variations, each with a unique message; Stay North, Stay East, Stay South, or Stay West. Because the directions are based on compass cardinal points, this type of buoy is called a Cardinal Mark. When both cones face up, it means Stay North [think of North being at the top]. When both cones face down, it means Stay South. It gets a little complex with east and west; the top cone up and bottom cone down means Stay East, and both cones facing into the middle means Stay West. I was taught to remember that the West Cardinal looks like the iconic hourglass waist and this keeps me in good stead. 

“when both cones face up, it means Stay North”

Once you’ve got to grips with the cones, the coloured bands are easy because the black band is based on the direction the cones are facing. On the Stay North buoy the black band is at the top, on the Stay South it is at the bottom, on the Stay West it is in the middle, and on the Stay East there is one black band at the top and another at the bottom. This means that if you spot the buoy for just a split second between waves, you only need to see one element [the cones, or bands] and you can tell which Cardinal Marker it is, and make sure you follow its guidance and stay away from the danger, whether it’s a wreck or reef. And at night the white lights are organised like a clock face matching the compass, with Stay East at 3 o’clock [3 quick flashes in 10 seconds], Stay South at 6 o’clock [6 quick flashes in 10 seconds], and Stay West at 9 o’clock [9 quick flashes + 1 long flash in 10 seconds]. Stay North is continuous quick white flash. 


In World War II the Luftwaffe developed a ‘Rescue Buoy’ for their downed airmen crash landing into the English Channel. The buoy was attached to the seabed by a long red and yellow striped rope that floated on the surface, helping the pilots spot which way the currents were flowing so they could land upstream and drift down to the buoy [tidal currents are so strong in the Channel you can’t swim against them]. They would then grab hold of the rope, climb onto the yellow buoy, clamber into a turret and drop down a ladder into a 43 square foot cabin with dry clothes, bunk beds, emergency rations, cigarettes, a surprising amount of cognac, and games to relieve the boredom. After drinking all the alcohol they would then raise a single ball and a red and yellow striped flag, and await rescue.


Eighty years on, there is a new revolution in buoy design; using them to generate renewable electricity from the motion of waves. The concept is that the buoy is connected to the seabed via a tether and as it bobs up and down on the waves it drives a piston within the generator to produce electricity. One design even uses this perpetual motion to desalinate water, an energy intensive process converting saltwater to freshwater. With only 1% of the earth’s water easily accessible for drinking, and with increasing droughts from global warming, these buoys are an ingenious solution to a problem highlighted by my naval grandfathers favourite saying, drawn from his experiences cruising along the shores of waterless deserts; “Water, water, everywhere - but not a drop to drink!”

In the next Sea Signs feature William will share tips for reading clouds.

About this series

Every day the sea is different, a  result of the ever-changing interaction between the moon, sun, tides, wind, waves,  buoys, boats and the beach. While the picture may appear complex, like a piece of classical music, it is essentially just an arrangement of simple elements, or notes. By dismantling the machine into its component parts and exploring each one in detail we can create order out of chaos; clarity out of confusion. That is the  purpose of this series 'Sea Signs'.

When we are young we learn to navigate urban environments; what traffic lights  mean or how to cross a road. What many of us aren’t taught is how to read nature’s  signposts; how to judge wind by watching birds or what weather different clouds  bring. Then there’s a whole technical world of buoys and boats with different light  sequences, colours and signals communicating messages. My goal in this series is to  share with you all the signs – both natural and man-made - that you may encounter in  your adventures along the coast so you can read them as well as any yachtmaster  skipper or crusty old seadog. 

With this knowledge, nothing is going to slip under your radar.

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