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: Sun Shots Through Clouds
    From: Greg Rudzinski
    Date: 2014 Nov 4, 06:11 -0800


    There is a whiff of hyperbole in Capt. Worsley's 1' claim. Especially when 3' intercepts are good from a small craft under ideal conditions. Perhaps under some conditions of fog his technique would be useful.

    Greg Rudzinski


    From: John Brown
    Date: 2014 Nov 3, 19:29 -0800


    Greg wrote: "A final important note is that the Sun needs to be positively identified and not just a bright spot in the clouds."

    Frank Worsley, Shackleton's navigator and Master of Endurance, describes his difficulties with cloud cover during the epic voyage of the 22 foot James Caird from Elephant Island to South Georgia in 1916.  His technique, when the disc of the sun was obscured by cloud and too indistinct to use either limb, was to bring the centre of the bright spot down to the horizon.  He claims in his book Shackleton's Boat Journey that averaging the altitudes could give accuracy to one minute of arc.



    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