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
    Silicon Sea II: Leg 48
    From: Dan Hogan
    Date: 1999 Mar 03, 7:32 AM

    Sight Reduction &
    Dead-Reckoning problem     Leg 48  030399   Test your knowledge!
    ----------------------     ------  ------   --------------------
    Our last position FIX was at 19:32:20ZT @ 17/02/1999(34d 00.0'S  153d
    30.2'E). Speed 8.7Kts, Compass Course/Course to Steer 89.1d. Var 12dE,
    Dev 2.5dE. Current Drift 17 mi/day, set 185.
    The distance log on the knotmeter indicates we have traveled 95.4 mi
    since our Last position FIX. The sky is brightening but we have a solid
    cloud cover.
    1)  What is the DR position at the 95.4 mi log reading?
        What is the GMT time and date?
    --  ---------------------------------------------------
    The wind begins to veer and we harden the sheets. Speed is 8.7Kts. 3Hrs
    and 20 min after our DR plot the wind heads us and we alter the Compass
    Course(CC) to 97.8d.  The Pilot Chart shows we are in a 13dE Var area.
    Dev is 2.0dE.
    2)  What is the DR position at our course change?
    --  ---------------------------------------------
    3)  What is the new TC?
    --  -------------------
    4)  What is the Compass Course Made Good?
    --  -------------------------------------
    We continue on this course for the remainder of the day. At 09:00:00GMT
    we take sights on the following bodies. As usual use the time of your
    first sight for plotting.
        GMT             Body            Hs
        09:00:00        Saturn          24d 13.1'
        09:05:22        Betelguese      47d 06.2'
        09:07:00        Rigil Kentaurus 11d 52.1'
        09:09:10        Miaplacidus     44d 13.8'
        09:15:19        Procyon         40d 22.3'
    5)  What is the DR position at the time of the first sight?
    --  -------------------------------------------------------
    6)  What is the FIX position?
    --  -------------------------
    7)  At the time of our initial sight there was a bright body low
        on the horizon at about 261d by the compass. What body was this?
    --  ---------------------------------------------------------------
    Lat & Lo = XXd XX.X', Date=DD/MM/YY, HE 9 Feet, Index correction
    -2.5', Time hh:mm:ss in UTC/GMT,unless otherwise stated. Silicon Sea II
    is a 34,000 lb(15.40t) displacement sailing vessel, 48' 3"(14.70m) LOA.
    39' (12.00m) LWL; Cutter rigged. Can tack to 45d. Water Tanks = 220
    gal(1000 ltrs). Fuel Tanks = 155 gal(700 ltrs). Fuel consumption .675
    gal/Hr at 8.5 Kts. Dist to Horizon: Nmi = SQRT HE@mtrs x 2.07; Nmi =
    SQRT HE@ft x 1.17.
    PLEASE respond with your results and thinking on these exercises to the
    NAVIGATION list at large. If you have questions or problems, A lot of
    folks on the list are knowledgeable and willing to help. Any questions
    or doubtful areas will be responded to promptly. Let us hear from you
    Good Navigating!
       -=The Navigation List Working Group=-
            Peter Smith  - psmith@wellspring.us.dg.com
            John Simmonds- mobi@netconnect.com.au
            Jim Manzari  - manzari@bluewin.ch
            Dan Hogan    - dhhogan@concentric.net
    Dan Hogan WA6PBY
    Catalina 27 "GACHA"
    =-=  TO UNSUBSCRIBE, send this message to majordomo@roninhouse.com:     =-=
    =-=      unsubscribe navigation                                         =-=

    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