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: Silicon Sea, LEG 13
    From: Mike Burkes
    Date: 2012 Sep 28, 12:07 -0700
    Hi NA,also my fix yielded 36 09.0N,10 59.4E very close to SS 13 of 36 08.9,10 59.3. If you require any more details I will be glad to supply them.
    Mike Burkes

    From: alberto.najar@gmail.com
    Date: Thu, 27 Sep 2012 21:47:26 -0300
    Subject: [NavList] Re: Silicon Sea, LEG 13
    To: NavList@fer3.com

    Hi Greg,

    Sorry, here we go: my problem was with the question 1. I think there is some thing wrong with the data. The text is:

    "Sight Reduction and DR
    Dead-Reckoning problem     Leg 13  XXXXXX   Test your knowledge!
    ----------------------     ------  ----------------------------

    On 12/05/96 we are at DR(36d 13.9'N  10d 54.4'E), on a TC of 111.3d at
    7.8 Kts bound for Masabb Dumyat(31d 30.1.N  31d 50.0'E).

    It is 19-42-00 ZT. We decide on a set of 3 bodies for a FIX During
    Evening Nautical Twilight.

         Body           Time           Hs             Zn

         Sirius          19-42-56       11d 46.2'      239.1d
         Alioth         19-48-27       61d 55.8'      035.8d
         Spica          19-54-40       31d 59.7'      137.5d

    1)  What is our FIX position using Spica as the plotting time?
        What is the Dist Off?"

    If we work these sights we will find some thing very bizarre. I found:

    LOP for Sirius
    12/05/1996 19:42:56 GMT
    Assumed Pos. Lat:36°13.9'N  Lon:10°54.4'E

    Hs: 11°46.2'
    Dip:-2.7' IC:-0.2'
    Ha: 11°43.3'
    Ho: 11°38.7'

    GHA: 65°20.5'
    Decl: 16°43.0'S
    LHA: 76°14.9'

    Hc:  0°46.9'
    Intercept:651.8 NM (towards)
    Az.calc:  248°

    LOP for Alioth
    12/05/1996 19:48:21 GMT
    Assumed Pos. Lat:36°13.9'N  Lon:10°54.4'E

    Hs: 61°55.8'
    Dip:-2.7' IC:-0.2'
    Ha: 61°52.9'
    Ho: 61°52.3'

    GHA: 334°28.3'
    Decl: 55°59.0'N
    LHA: 345°22.7'

    Hc: 67°54.3'
    Intercept:-361.9 NM (away)
    Az.calc:   22°

    LOP for Spica
    12/05/1996 19:54:40 GMT
    Assumed Pos. Lat:36°13.9'N  Lon:10°54.4'E

    Hs: 31°59.7'
    Dip:-2.7' IC:-0.2'
    Ha: 31°56.8'
    Ho: 31°55.2'

    GHA: 328°16.3'
    Decl: 11°08.6'S
    LHA: 339°10.7'

    Calculated Altitude (Hc): 38°43.1'
    Intercept:-407.9 NM (away)
    Az.calc:  153°

    Thank you very much,


    2012/9/27 Greg Rudzinski <gregrudzinski@yahoo.com>
    Ahoy Alberto,
    You will need to provide a link or details of Leg 13. Then I'll do a plot.
    Greg Rudzinski
    [NavList] Silicon Sea, LEG 13
    From: Alberto Najar
    Date: 27 Sep 2012 15:08
    Dear All,
    My name is Alberto Najar, I'm from Rio de Janeiro, Brazil and I regularly practice astronomical navigation in my 33 foot, a Peterson sailboat. Some days ago I was trying to solve LEG 13 from Silicon Sea and I didn't find the same results for the question 1 - the fix position - at all. I was wondering if there is something wrong. After searching in list archives and not finding anything, I decided to post a message in the hope to find any help.
    Thank you in advance,
    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