The natural Navigation: The Right Course, Naturally

A weekend of sailing has just passed, one that was full of meteorological kindness.

Nature was generous in two ways over the weekend – perhaps as a reward for my having set up a page of weather lore?

Firstly, blue skies, fair winds and warm sun ruled over the Solent. Secondly, an approaching warm front signalled its intent, in line with meteorological science and common folklore, by sending a team of mares’ tails ahead. These cirrus clouds would be followed by cirrostratus, altostratus and then the rain-bearing nimbostratus. A show was being promised, and then put on.

Our good fortune continued on Sunday, when we were given a ringside seat to watch the nimbostratus, but never had to get too close. The dark grey clouds advanced slowly and pressed down to the west of us. The rain fell barely a mile from our small Contessa 32, but by the…

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The tops of the trees are just visible in silhouette against the clouds that are lit up by the moon. That is Jupiter to the right.

Happy Equinox All!

At nine minutes past three this morning, GMT, the sun was overhead the equator.  To celebrate, here are a few things that you may or may not know about the equinox. Only one of them is not true.

The sun will rise due east and set due west for everyone today.

The direction (bearing) of sunrise and sunset changes by more each day at this time of year than at any other time.

On the December side of the equinoxes the sun is always overhead the southern hemisphere, on the June side it is always overhead the northern hemisphere.

Everyone on the planet shares an equal length day and night on the equinoxes.

Satellites that appear stationary and stay over the same spot on the Earth’s surface are called geostationary or geosynchronous and they remain in orbit over the equator. As the sun passes over the equator…

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Once more my pre-dawn ‘Batsense’ kicked in and I awoke before five with an urgent desire to go outside. It was not the pressure on my bladder, I do not think, but the idyllic conditions and night sky players that were beckoning me.

Orion and his sword were first to offer their greetings and then I noticed Jupiter still visible in the southwest. Sirius, Betelgeuse, Capella, the Plough and Polaris sketched out some order in the celestial sphere.

The moon was close to setting and was lighting up rows of fluffy cumulus clouds on their western edges. As time passed the clouds lost their bright white western edges, but gained pink and orange eastern ones. They moved sedately towards the northeast, signalling the start to a fine day. (Photo to the right was taken a few minutes ago.)

My thanks to Kevan Hubberd for sending in the idea about using Orion’s Sword as a way of finding south.

Orion’s Sword can be seen in the image to the left as the short vertical line of ‘stars’ under Orion’s Belt.

The Sword does indeed point to a spot on the horizon that is close to due south when the Sword is near vertical (as in this image), but it is a less dependable guide when it is well off-vertical, ie. when it is lower in the sky.

Technical bit for natural navigation zealots only: The reason that the Sword is more accurate when vertical is that it makes a line in the sky that is parallel to the line towards the south celestial pole. When vertical this line intersects with the horizon at a point very close to due south, but at times when the sword is closer…

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The sort of morning that navigators dream about. A stroll around the National Maritime Museum in Falmouth. No agenda, just a meander.

I had been aching to visit for a long time, but even with my predilection for getting around a bit, Falmouth is not en route to many places and so it took a while to find the right excuse. The perfect excuse turned out to be: “I want to go to the National Maritime Museum in Falmouth and so I am going to go to the National Maritime Museum in Falmouth.” Said without, I must emphasise, any hint of Lesley Gore.

What pleasures and treasures lay in store! A theodolite used by Admiral John Lort Stokes on his surveys of the Australian and New Zealand coasts. A whole heap of lighthouse paraphernalia. And a surveyor’s chain that measured 22 yards, naturally, since a chain is…

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The past few days have seen me bouncing between meetings in London – pinging between Kensington, White City and Theatreland. Throw in a Tube strike on the Tuesday and the stage was set for some urban natural navigation.

The sun, trees, churches, clouds and satellite dishes all played their parts, but there are so many lesser known roles in the epic production that is ‘City Navigating’.

As if to prove this I received a message a couple of days ago from someone who had read the book and got in touch with some intriguing urban ideas. Clem McEwen drew my attention to two methods which sounded familiar, but which are certainly not well known to me, or used by me… yet!

1) Street numbering. Streets are normally numbered in ascending order away from the centre of a town, with the numbers 1 and 2 being closest to the centre, normally…

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BBC Devon have a delightful story about the sculptor, Marcus Vergette, on their section of the BBC website.

Marcus is sculpting a series of ‘tidal bells’ that will ring out at high tide around the country. There is no mention of springs or neaps in the article, so I’m presuming the bells are being placed low enough to ring at a neap tide (the narrowest range between high and low).

In the book I touch on the fact that humans have become very adept at approximating tidal behaviour, but it is still impossible to predict tidal times or heights with absolute precision. The tides are influenced by the orbits of the Moon about the Earth of course, but also very significantly by the orbit of the Earth around the Sun, which fewer people realise. These are the factors that are relatively easy to predict. The effects of…

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My thanks to the RNLI, who gave me the opportunity of going to sea with them this afternoon.

They were also kind enough to let me quiz them about their methods of navigation. As you might suspect, the sun, moon and stars don’t play a big part, but they do have some fantastic kit. The Tamar class of lifeboat that we went out on is a formidable boat and the crew’s eyes really light up when you get them on the subject of how good the boat is at righting itself from being upside down.

The only major navigational surprise for me was that they don’t currently use AIS (Automatic Identification System). Warming to know that they do still carry paper charts and mark their position every quarter of an hour with a low-tech pencil.

It was only a Force 5 or 6 out there today, but as…

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For the love of God, spare us from any more blog titles like that, you are thinking. But persevere, there is a point to it. Somewhere.

I have just spent a fun 24 hours near Abergavenny, on Sugar Loaf Mountain (to give the big hill it’s superior title). I was joining some of the BBC Wales team.

The day reminded me just how easy it is to avoid the crowds. If work and other more important things allow, then the start and end of the day are the times to be on mountains, up to a certain altitude anyway. I can remember cuddling a friend in the lee of an igneous rock outcrop a few hundred feet below the summit of Mt Rinjani in Lombok, Indonesia. Not a twin bedroom, I hasten to add. We shivered violently in wet clothes praying that the dawn’s sun would get…

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