Shooting Stars
May 5, 2019
Day 212
Noon Position: 15 13N 44 31W
Course(t)/Speed(kts): NW 7
Wind(t/tws): NExE 12
Sea(t/ft): NE 5
Sky: Cumulus
10ths Cloud Cover: 3
Bar(mb): 1019+
Cabin Temp(f): 84
Water Temp(f): 78
Relative Humidity(%): 61
Sail: Working jib full; main one reef, reaching on starboard
Noon-to-Noon Miles Made Good (nm): 162
Miles since departure: 28,667
Avg. Miles/Day: 135
Leg North Miles: 5,711
Leg North Days: 46
Avg. Miles/Day: 124
Six days over 160, and we’re still cranking.
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I’ve been at astronav consistently since rounding up into the Atlantic forty six days ago, and yesterday marks a turning point.
Yesterday, I switched off the chart plotter.
The sextant I use is the Celestaire Astra IIIB. I bought it in 2005 from my local chandlery because it was the only sextant they sold. Not the only brand; there were no others in the store. I was about to make my first ocean crossing and wanted to learn celestial enroute but lacked the basic tools. This sextant looked like serious business and came in a lovely mahogany box and wasn’t too expensive. So I bought it without further ado and have been using it on passages ever since with great success.
With one exception. Stars.
Star sights are typically taken during morning and evening twilight, when the higher magnitude bodies begin to appear but the horizon is still visible. And I have tried often at sea to shoot stars during this time. I’ve done well when I can find the damned target, but that’s the tough part. Stars can be very dim.
The Astra IIIB came with what’s called a Whole Horizon Mirror (sitting next to the sextant in the photo). This is a coated lense that allows the user to see the whole ocean horizon with the image of the body (sun, moon, or star) superimposed onto his field of vision in its entirety. This lense is excellent for bright objects and makes “racking down the sun” a breeze.
But I found that the coatings on the lense applied just enough shading that seeing stars was difficult. To be fair, there are other factors, one of which is that I wear bifocals; another is that Mo is rarely a stable platform from which to find a pinprick of light in the heavens.
When I broached this issue with Celestaire, Ken Gebhart immediately recommended I try the Traditional, split mirror (attached to the sextant in the photo). This is the technology that every sextant employed before coated lenses were invented. And one benefit of the Astra IIIB is that it is designed to facilitate easy mirror swaps.
The split mirror is just as you’d imagine. Half the lense is mirrored and half the lense is clear. Thus, half of the image one is seeing is unadulterated horizon and half is of the sky in which resides the body being racked down. This playing halvsies with the image can take some getting used to and is a bit more difficult on a bounding boat, but there is no shading on this mirror.
And this has made all the difference for me. Now the stars I pursue are as bright in my scope as they are with the naked eye. For a couple weeks I’ve been shooting both sun and stars with the split mirror and feel I’ve made the transition.
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Having, now, better access to stars, planets, and the moon means that I can get two or three widely separated (morning, noon, and evening) fixes on a day with good visibility, and this has been encouragement to take the next step.
It has dawned on me only slowly that the sextant work is the easy part. What’s hard is keeping track of one’s position in the interim; that is to say, dead reckoning. This moment-to-moment knowing is something that the chart plotter does with such ease, that unless it’s decommissioned, one has no incentive to get to know the compass or the log. Why learn to like oatmeal if someone delivers strawberry waffles to your bedside each morning?
So, it’s off. And I’m not lost. I don’t think…
To be honest, it’s not entirely off. The chart plotter is my AIS interface, and I still want the noon-to-noon mileage numbers, so the screen is off while the unit runs in the background. And I am relearning the mysteries of variation and deviation.
Bravo, Randall, for taking the leap! My Astra IIIb has served me well on the ocean voyages I have taken — but always with GPS to check my work.
Wow, you’re no longer an accomplished ‘yachtsman’, but rather a fully qualified, bona fide mariner now—a true ‘old salt’. Although, you mostly merited this status after the first month, or so, now there is absolutely no longer any “mostly.
‘Good on ya’, Randall, as my Aussie mates taught me to say. We relied heavily on our sextant – don’t remember the make now – during
our 1994 2 handed voyage from the Caribbean to Australia. We had GPS but the accuracy was less than spectacular in those days, and in any event, without fail, it would go into “Searching for Satellites” mode whenever we approached land – go figure!
Robin & Maggi Ansell – late of s/v Orca, now an artificial reef in the Coral Sea courtesy of cyclone Justin.
Well done brother! I admire your courage and think you’re being incredibly wise to get yourself weaned from the plotter. It’s only if you actually rely on the celestial navigation when you’ll know for sure you can get by if you lose al your electronics. Wish I could say that… praying for you to have fair winds and comfortable seas.
Fun to partake via blog on your voyage, and inspiring to watch you learn. What do you have on board to measure speed/distance thru the water other than a transducer? Figure you must have a sense for that, now. Always monitoring and now a new tool in your bag of tricks. Best going forward, hope the ice breaks up early for you!
Wonderful mileage! Must be so thrilling to be making such great daily runs! Randall, the only navigational equipment we had aboard KANDARIK’s circumnavigation in 1985 – 1992 was our Walkers Log!!! now that is going way way back, and of course our Zenith Trans Oceanic Radio for time ticks from Fort Collins Colorado, and out Plath Sextant with split mirror, stop watch, and The Sun, The Moon, and the Stars! Like you, the routine daily was morning, Noon, and afternoon sights every day the sun was there for us, and we only used the stars or lower limb of the moon, when approaching land after a long passage! As you say, once you get used to it, there is something rather special about this time honored means of navigation and it becomes so routine, but very important, to daily navigation. Many many years later my husband, Andy, would joke and say, “I bet Captain James Cook would have given his first born for a GPS!”