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I've been following with great interest, if with less than complete 
comprehension, the recent threads on finding position at and around noon.

I'd like to divert a tiny new rivulet from that stream-- a back-to-basics 
thread on noon sights for latitude. I don't like those titles for how-to 
books that end in "...for Dummies," so I'm using the kinder term "...for 
Beginners."

I've been working the latest Nav Problem in Ocean Navigator magazine, and I'm 
finding I can't get the latitude the editor does from the noon sight data 
presented.  My main stumbling block seems to be that the time given for the 
shot is not the time I consider Local Apparent Noon for the DR longitude 
used.  Wouldn't that be essential?  If the sun is observed at 12 minutes or 
more after LAN, how does one account for that difference?  

My main source of instruction is Dutton's (12th edition), which I find usually 
gives excellent and thorough explanations of procedures.  The article on 
latitude by noon sun focuses on how to determine LAN and what to do with the 
Ho obtained then.  I've found nothing so far about accounting for a time 
difference and the fact that the sun is not at its zenith when observed 
before or after LAN.  Much is made of combining the vessel's change of 
position east or west with that of the sun to pinpoint LAN, but the magazine 
problem provides no data about course or speed.

I'll bet one you can tell me somnething that will make me slap my forehead and 
exclaim "Of course!"  Fire away!

Thanks in advance,
John P.






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