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
    New Moon, Perigee, and Solstice
    From: Frank Reed CT
    Date: 2003 Dec 21, 19:44 EST
    It's about six hours until the winter solstice right now, and I for one am looking forward to lengthening hours of sunlight.

    This weekend is also New Moon and Lunar Perigee. The HP of the Moon is maxing out at about 61.2 minutes. Of course, with the Moon so close to the Sun, I am forced to rely on dead reckoning for a few days to determine my longitude... ;-)

    On the other hand, the coincidence of New Moon and Perigee also make this a great weekend to watch the ocean tides. The tidal range in southeastern Connecticut depends strongly on the Moon's distance so we have a significant tide range this weekend. My little web site for cell phones and other devices with small screens includes basic tide calculations for local sites near Mystic and a couple of others (URL: fer1.com).

    These tides bring to mind something I noticed in old editions of Bowditch. If I am remembering correctly, Bowditch from c.1800 says that the Spring Tides (tides with maximum range) occur about three days after New Moon and three days after Full Moon. That's not accurate in New England where the difference is less than a day, but it is fairly accurate in northwest Europe which has unique resonances. Bowditch, of course, copied earlier works and carried over lore regarding European tides. So when did they fix it? Is there a 19th century edition of Bowditch that has better basic descriptions of tidal phenomena?

    Frank E. Reed
    [X] Mystic, Connecticut
    [ ] Chicago, Illinois
    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)