The natural Navigation: The Right Course, Naturally

Last night I accidentally stumbled on one of the best images of ocean swell that I have come across. I was looking at Essaouira on Google Earth and happened to notice that the image showed some really clear swell patterns.

In this image we can see the sets of swell arriving from the top-left of the picture (northwest). We can then see the distinct and different patterns that are formed as these swells interact with Mogador island off the coast of Essaouira. The swell diffracts through the gaps either side of the island and then these two patterns meet again in a thin line that runs from the top of the island to the land just above the large breaking wave.

Down at sea level it takes a lifetime to interpret these patterns, but it is so much easier to see how the great Polynesian and Micronesian navigators would have…

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Just back from a bracing and invigorating couple of days on the water. My wife and I sailed from Chichester to Cowes, where we met up with the Contessa 32 Association’s Christmas Rally.

The sail back today allowed us to revel in one of those winter days that make the others more bearable. Barely a cloud in the sky, Force 3 or 4 sailing all the way.

Here is a riddle for nautical navigators:

At about lunchtime today I took this photo from our yacht. What is slightly strange about this picture?

As usual answers on a postcard or by email.

UPDATE:

The answer, which Captain JP got spot on, was that if we are looking towards the sun at lunchtime then we must be looking close to south. Ie. The picture was taken from the north of a south cardinal.

Navigation may fill my working hours, but even I couldn’t pretend that it is a high profile topic. Last week however a story about cows pointing north and south started appearing everywhere, there is a good summary on the BBC website.
On Saturday the Times newspaper ran a main news story and editorial piece describing how GPS navigators are not getting the full experience and are being denied the benefit of the rich detail of traditional maps. They put it well, ‘Turn left on to the A303 for Andover, ignoring the ancient stones: those without a map may not know they are passing Stonehenge.’
Perhaps this mini-surge of interest is why they were kind enough to run a snippet about my courses too.