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: Pilot charts
    From: Gary LaPook
    Date: 2008 Apr 16, 23:06 -0700

    Gary LaPook writes:
    All of the roses on the chart are "wind roses" and should all be blue
    but there appears to be some problem with my scanner. The current
    arrows are green and are not associated with roses.
    On Apr 15, 11:11 pm, "Andres Ruiz"  wrote:
    > Dear Gary,
    > Such strong currents no exist. 30 is not the speed, is the percentage of 
    occurrence in current direction.
    > Reading Current Roses:
    > Like the wind rose, the current rose graphically, (attached pic), depicts 
    numerous current characteristics such as percentage occurrence of current in 
    eight compass directions, and speed in knots of the current.  The length of 
    the 8 lines radiating out from the circle indicates the percent occurrence of 
    current FLOWING TOWARDS each compass direction.  The longer the line the 
    higher the occurrence in that direction.  If the length of the line exceeds 
    the area available to display it (approximately 30 percent), the actual 
    percentage is displayed.  The number of feathers on the line indicates the 
    speed in knots of the current in that direction with each feather 
    representing 0.2 knots.
    > -----Mensaje original-----
    > De: NavList@fer3.com [mailto:NavList@fer3.com] En nombre de Gary J. LaPook
    > Enviado el: mi�rcoles, 16 de abril de 2008 1:43
    > Para: NavList@fer3.com
    > Asunto: [NavList 4842] Re: Pilot charts
    > glap...@pacbell.net wrote:
    > I have attached a portion of the January Pilot Chart of the South
    > Pacific Ocean published by the Defense Mapping Agency. Until I looked at
    > this chart I had no idea that currents in the South Pacific could be so
    > strong. The green arrows show the current  direction and speed in knots.
    > For example, the current shown passing the southern end of New Zealand
    > is 10 to 20 knots! And in the Gilberts it shows up to 30 knots! How do
    > ships manage to maneuver against such strong currents?
    > gl
    >  Current Rose.PNG
    > 1KViewDownload
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@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