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: Horizontal Sextant angles plot.
    From: George Huxtable
    Date: 2010 Nov 29, 21:02 -0000

    Byron wrote-
    "My luck was with me, I was reading a magazine to my daughter and I noted a 
    statement and a drawing stating “an angle from the circumference of a 
    circle is one half the angles to the center of the circle. This gave me an 
    idea that I did not need Fry table, I hoped to show GITMO a new way and 
    gain their confidence and high score for the ship's ability to handle any 
    Navigation situation. Before leaving Rhode Island We trained and tried this 
    new idea. We got underway for our trip to GITMO, At GITMO. The first 
    underway test, we use the bearings and plot on the chart as normal. The 
    instructor stated your” Gyro is down,” We jumped into using the Sextant and 
    the three armed protractor. After several fixes, they stated your three 
    armed protractor is broken we immediately jumped to our new system which 
    was several diagrams on the chart between two sets of NAVAIDS, using a 
    compass with lead I scribed circles that intersected for our position as we 
    move out the harbor. They had never seen this before with the new design 
    that I had placed on the harbor chart, they stopped the exercise and 
    inspected and asked questions about the design on the chart, and gave us an 
    outstanding grade... "
    Byron seems to be describing the geometry for constructing a position 
    circle through a pair of landmarks with a known included angle between 
    them. He deserves credit for working that out from first principles, back 
    in 1969.
    But around that same time, at a yachtsman's navigation evening-class in 
    Britain, I was being taught the same technique, and it is detailed in 
    Cotter's "Elements of Navigation" of 1953, and likely many other texts of 
    earlier date. So it's a surprise to me that such a well-known procedure, on 
    this side of the Atlantic, appeared so novel to the top navigational brass 
    of the US Navy.
    contact George Huxtable, at  george@hux.me.uk
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. 

    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