Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Level of observation accuracy in medium seas
    From: Jared Sherman
    Date: 2004 Jul 23, 11:38 -0500

    Sorry to say, no. Only that I did re-read it someplace this or last year and 
    say to myself "Ahah!" and making a pointed mental note of it, with the link 
    that last time I went out in "4-6 waves" and they were very much 8-10 to 
    everyone on board, that explained the difference.
    
    >
    > From: David Weilacher 
    > Date: 2004/07/23 Fri AM 06:42:03 CDT
    > To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
    > Subject: Re: Level of observation accuracy in medium seas
    >
    > Hi Jarad;
    >
    > Can you point me to your source for Noaa wave height definition?
    >
    > Dave W
    >
    >
    > -----Original Message-----
    > From: Jared Sherman 
    > Sent: Jul 22, 2004 9:34 PM
    > To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
    > Subject: Re: Level of observation accuracy in medium seas
    >
    > Dave-
    >  <50 foot waves with a mile between peaks.  I take my shot when my boat is
    > at the top of a wave.  This is easy to tell because I can actually see a
    > horizon.  The horizon I see is 8 miles away.>
    >  Seems like short horizon. NOAA says that waves are measured from the sea
    > level, not from the trough to peak, so are you talking about real fifty foot
    > waves, or "real" 50 foot waves, which most sailors would call hundred
    > footers?
    >
    > If the former, you're observing from 25' above sea level, figure ten more
    > for your deck and standing eye height, since you've got a good enough grip
    > to rider those doggies. That's 35' asf now, about your eight miles.
    > (7.9+)
    >
    > Nah, you're only in 25' waves, that's the problem. Wait for rougher weather,
    > you'll get a better horizon.
    >
    > But you could certainly figure the math. A sphere (close enough) 25,000
    > miles in circumference, two points 8 miles apart on that. Change the radius
    > of one by the 25' your far wave is blocking you...run some tangents and
    > angles..."A simple exercise left to the reader."
    >
    > Just remember, you're only in 25' waves.
    >
    >
    > Dave Weilacher
    > .US Coast Guard licensed captain
    > .    #889968
    > .ASA instructor evaluator and celestial
    > .    navigation instructor #990800
    > .IBM AS400 RPG contract programmer
    >
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    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