Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    Name or NavList Code:
    Email:
       
    Reply
    Re: Distant Horizon
    From: David Pike
    Date: 2023 May 17, 03:13 -0700

    Homer Smith
    Re: your lake horizon question.  The best thing to do is try it and see.  You could compare your result with Frank's GPS Anti Spoof App.  The dip tables certainly go that high.  They used that technique on the R34 Airship Atlantic crossing in 1919. Their problem was not the dip tables but knowing their exact height when no updated surface pressure was available.  They got round this by shooting the length of their shadow. You don't have that problem because you know your height above sea level.  Your problem might be knowing the height of the water in the lake.  However, the overall error could be small, because when you look at the dip tables you'll see the difference in dip for a small error in height reduces with the height above sea level of the observer.  Incidentally,  It depends upon where you live, but near me the days when you can actually see the horizon 34 miles away are relatively few.  Altenatively, use an artificial horizon or buy a decent bubble sextant. The photo is from Norie's 1963. DaveP

    File:


       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID Code:

    Custom Index

    Subject:
    Author:
    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