Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding

Compose Your Message

Add Images & Files
    Re: Another "emergency navigation" sight reductionmethod
    From: Lu Abel
    Date: 2015 Jul 15, 01:13 +0000
    Excuse me, Gary, but who said that all sight reductions must be done by table (which, if I read your note correctly is what you claim)??

    In fact, there are some who, at the beginning of this discussion, said "what's wrong with packing a small, solar-powered calculator in the ditch bag?"  Or others (including me) who noted that it's highly doubtful that one would be doing any "navigation" whilst drifting in a modern liferaft.

    If you want to call for a better title for this particular discussion, I'd vote for something like "ultra-compact sight reduction tables."

    From: Gary LaPook <NoReply_LaPook@fer3.com>
    To: luabel{at}ymail.com
    Sent: Tuesday, July 14, 2015 8:56 AM
    Subject: [NavList] Re: Another "emergency navigation" sight reductionmethod

    BTW, I don't like calling these "emergency navigation" systems. That implies using a less accurate system for celestial navigation in emergencies whose only advantage is that they are compact so as to fit in a ditch bag. This seems to say that you use the most accurate standard system everyday, carrying the entire set of HO 229 in your small boat, and will  use the bastardized system only in an emergency. What we are actually talking about are different methods of clestial navigation, that just happen to be compact, but that should be used every day for normal celestial navigation, leaving the entire set of HO 229 at the dock. Most navigators have apparently shifted to using HO 249 to save the considerable space (and weight) of the ultimate set of tables, HO 229, and find the level of accuracy in HO 249 accptable for practical navigation and the Bygrave and Hav-Doniol (and others) provide the same level of accuracy in very compact forms. 

    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