Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    HO 208 vs Compact NA tables.
    From: Mark Coady
    Date: 2015 Dec 8, 10:09 -0800

    After reading the reccomended "Self Contained Celestial Navigation with HO 208" and working through a number of sight reductions with HO208, I was intrigued enough to try to hunt up a copy of the table itself for use without abusing my book.  I found the simple explanation good for my simple mind, and the solutions straightforward and understandable.

    Failing to find a .pdf on the first attempts, I managed to find a beautiful conditon US Navy Department Copy for my library.   It is wonderfully compact.  (of course now I can't use that, its an heirloom from 1935 LOL.)

    I kind of fell in love with its austere cookbook simplicity as an emergency and practice backup with just a pencil. I first learned on HO 229 in print version, and pdf's of HO 249, with its good points....

    It set me to thinking why I ignored the compact tables in the NA (i always figured I could learn them quickly in a pinch), which is a similar idea of breakdown into two triangeles. 

    In trying to research it, the NA tables have a stated accuracy to 1' of angle, which may increase to 2' with rounding errors.   HO 208 the statement I have found is a few tenths of minutes.

    Ho 229 i supposed to be .1, but my understanding from real life calcs is its more like .2 to .3, creeping it closer to the very popular 249.

    Obviosly I am picking over jellybeans, as any of them can get the sailor home.  I was just curious if anyone knows the verified computational accuracy of HO 208 vs the NA tables, and has anyone else found the compact simplicity refreshing as an alternate method for occasional use. (heck the whole thing fits in my waterproof sextant box)  (makes me wonder about 214, which I have never used)

    I think the real story is I found the explanations so clear and concise , thereby really increasing comfort, as I got right answers out of the chute  first time without any futzing whatsoever.

    I love the thought  of something that makes finding right answers cookbook, even when cold, tired, and stupid, and everything else seems to going wrong.

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site