Wednesday, 27 November 2019

Mother with a sextant

Today has been an easy day, with glorious sunny weather and great food from the galley, but it has also been a frustrating day as the trade winds remain as illusive as ever and we continue to motor south. The watches on Hera change every three hours and as usual I am on watch from 3am to 6am when Andrew takes over. I do a short handover and then go back to my bunk for a few hours. Oults is on Mother Watch today, which means that he runs the galley, making all our meals, serving drinks and generally doing any housekeeping, and by the time that I surface from my cabin he is already preparing breakfast. It's remarkable how the smell of cooking draws everyone from their bunks and we congregate around the saloon table for cereal, scrambled egg on toast and freshly brewed coffee.

The sky is blue and the temperature has started to warm up and soon
everyone is in the cockpit, reading, chatting or in my case studying the
weather models at the nav station, searching for a route out of the light
airs. There are no easy answers, so we continue on our southerly course,
still close to the coast of Africa, waiting for the wind to increase and
we can head towards our destination. There is a large trough of light airs
to the west and we have to get south of it before we can set sail, so we
motor along over the flat calm sea at 6 knots, alternating the engines,
using one at a time to conserve fuel. Mervyn settles down with his book
on the bimini roof, Rosie is on watch at the helm, Andrew has his nose
buried in his phone, I'm not sure why, and Oults emerges from the galley
clutching his sextant.

It is nearing the time to take a sun sight and those of you who know Oults
will know that once he has his mind set on something, he is like a dog
with a bone. Taking a sun sight with a sextant is best done when the sun
is at its zenith, known in celestial navigation circles as local noon. By
taking a series of sights, essentially the angle between the sun and
horizon, a few minutes before local noon, one can deduce the exact angle
at local noon when the sun stops rising and starts to fall, and this
equates, more or less to one's line of latitude. The only problem is that
we need to know roughly when local noon will occur and Oults starts taking
sights at midday on his wrist watch which is set to GMT. However local
noon isn't midday, not even close, and after covering several pages of his
notebook with angles that keep increasing, as the sun keeps rising, he is
called back to the galley to serve lunch. Another couple of sights between
salad and pudding and still the sun rises. As we are quite far west of
Greenwich, in fact about 1,000 miles west, local noon is in fact nearer
1pm than 12 midday, but Oults, ever the traditionalist, eschews our
satellite GPS, which tells us local noon to within a scintilla of a nano
second, and continues to take sun sights in the way that navigators might
have done a hundred years ago, a period when he would much preferred to
have lived.

Eventually the sun starts to fall; however there are large gaps in the
sights caused by pudding, coffee and delicious little Magnum choc ices,
and he has to estimate local noon which seems to have occurred around the
time that the oranges were being peeled. After washing up he then retires
to the squiggles of his note-book to do his sums, emerging triumphant with
a grin on his face. In fact it seems that the news is mixed; his latitude
reading is extraordinarily accurate but because of his rough approximation
of local noon his longitude places us mid Atlantic, where unfortunately,
we are not.

Apart from providing entertainment for the crew, and additional challenges
to Oults' catering, this exercise demonstrates the importance of accurate
time keeping when navigating. In 1707 in a single accident, 4 home-bound
British warships ran aground on the Scilly Isles killing two thousand men
because the navigators miscalculated their position; they didn't know the
accurate time - a bit like Oults. In response Parliament passed the
Longitude act of 1740 (note the 33 year gap), which awarded a prize
equivalent to several million pounds to anyone who could calculate
longitude, with an accuracy to satisfy the Astronomer Royal and the
commissioners of the Royal Society. A clockmaker called John Harrison
designed and built a clock that could tell the time to within seconds, and
also survive the hardships of a British warship on the high seas, and
eventually in 1773, after much prevarication, George III paid out the
prize to an aged and exhausted Harrison.

For dinner, Nick is back in the galley, preparing fish stew with
gremolata, with the added bonus that during the afternoon Mervyn catches a
fish; so instead of frozen cod we use Mahi Mahi, still warm from the
Ocean, and the result is delicious. The U-shaped galley is opposite the
saloon table, which places added pressure on Mother, whose culinary skills
are on full display to a hungry audience, waiting and watching with
anticipation. After dinner everyone slips away to their cabins and
darkness descends once more on the boat as another day comes to a close.
Above the stars are even more vibrant and below, the phosphorescence
streams out behind us, glowing with pulses of light.

No comments:

Post a comment