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: Sextant Accuracy and anomalous dip.
    From: Jared Sherman
    Date: 2003 Mar 17, 23:20 -0500

     If I understand this correctly then, when the air is warmer than the sea, the 
    observed altitude is too small. And conversely when the sea is warmer, the 
    observed altitude is too large.
     But one minute per six degrees F seems like it is big enough so that it 
    should have been a "routine" correction in sight reductions, rather than some 
    obscurity to be dug out of an old Bowditch. With a winter ocean near 32F on a 
    cold 5F day...that's an easy 4-5 minute error in the readings! Ditto for 
    those lazy days when the water is near 70F but the air has been pushing the 
    high 90's and local heat from a beach seems to be boiling the air even more.
     It just seems odd that an error of this magnitude would be routinely ignored.

    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