Been looking at the ARC

Re: costs

Did consider going down that route, however I wanted a system that would be totally independent of other things, after all if you are going to have the almanac in the laptop, then you can also use one of the many programmes for calculating positions from the stars. If you dont want the annual almanac there are 5 year versions, however these complicate the arithmatic more cause they need additional calculations.

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Re: costs

you don't have to rely on the computer continuing at sea. i generally print off the months i need and take them aboard, it's just a cheap way of getting an almanac

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Re: Almanac on laptop

it's called 'Almanac' from Keyboard Marine Software. bought at the boat show about 10 years ago.

it has one of those evil anti-copying locks that allows a limited number of installations.

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Re: costs

You don't really need a nautical ephemeris or sight reduction tables, either tabulated or on computer, for the most simple type of sight reduction using the sun. The short method explained in the <A target="_blank" HREF=http://www.davisnet.com/product_documents/marine/manuals/mark15.pdf>Davis Mk 15 handbook</A> will provide moderate accuracy, given a sextant (for latitude), an accurate watch (for longitude) and the table of the "equation of time" that is provided. This is quite a good way to get started with astro-nav, and was widely used in the C19th by ship's masters who struggled with more complex mathematics. Incidentally, the "equation of time" is often found pasted inside sextant cases, specially lifeboat sextants.
 
Talbot, and those others who still can use this instrument, you put the rest odus to shame. I hthnk I will start loking up the relevant text books. Thank you for all the info.
Regards, Becky

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> Talbot, and those others who still can use this instrument

Learning how to do sun-run-sun astro navigation is the least labour intensive route to nautical street cred I can think of. This entry level astro takes a fraction of the time to learn compared to becoming an expert in ColRegs and light signals.

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<put the rest of us to shame>

your comment really illustrates the unjustified mystique that astro has.

the classic case of sextant phobia was a french sailor called Waquet in the 1968 OSTAR who was so terrified of astro that he set up an arrangement with Air France to give him his position as they flew over. There was a strike just before the start. the official lists showed him "retired - unable to navigate". that someone should go to those lengths rather than try to learn a few sums shows how scary it can seem.

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Isn't it what kept the crew from mutiny and murdering the officers in the dark ages? Only the super intelligent man with the sextant could get them home again!

The modern equivalent perhaps is the man who knows how to program the video - or the GPS.

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>
 
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