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
    Re: Beginning celestial navigation method
    From: David Pike
    Date: 2020 May 15, 02:24 -0700

    Hello Grace O’farrell
    That’s great stuff and good to see.  The Moon and the Southern Hemisphere meant I had to put my thinking cap on.  Air navigators tend to avoid the moon if they possibly can.  I followed most of your working and ended up with the same azimuth and intercept as you, but I used spherical trig directly.  I’ve not really studied maritime tables in any depth, but you’ve prompted me to try.  I’ve got my dad’s stuff on my bookshelf.  I see what you mean now about the minus 30 for the upper limb.  It’s a ‘gotcha’. 
    An air navigator would have approached the problem slightly differently.  They would have used an assumed position of 5°S 071°015’E. That would have given round numbers for latitude and LHA.  You could go into air navigation tables with those and come out with Hc and Z in seconds.  We use bubble sextants and aim at the middle, so we don’t need to worry about dip and semi-diameters.  You get the same position line within a mile, but the intercept is different, because you plot it from a different starting position. Here’s hoping you’re not too badly restricted by the Covid crisis and that the Cruise Industry will be up and running again soon (Sorry, I looked you up on LinkedIn!).  DaveP


    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