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: A credible AIS track for the Costa Concordia
    From: Jaap vd Heide
    Date: 2012 Jan 25, 14:10 -0800

    It is all a matter of keeping the centre of gravity (well) below the metacentric height.
    When for a given situation it isn't, or the distance is to small, you take in ballast.

    See also http://en.wikipedia.org/wiki/Metacentric_height

    Risky: partly filled ballast tanks or compartments: when the so called "free surface area" becomes to big and the boat heels for some reason, the water that has been taken in intentionally or unintentionally will flow to the lowest point, thus only adding to the heeling force. Which in most cases will mean adding to the problem.


    Lu Abel wrote:
    "I nonetheless have to wonder how any amount of water ballast 20 or 30 feet below the water can right stem-to-stern steel superstructures 100 feet above the waterline from all but the most trivial heel."

    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    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