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    Re: Plotting charts: WAS: Re:
    From: Jeremy C
    Date: 2009 Nov 15, 14:53 EST
    Plotting sheets are used in the middle of the ocean to provide a larger scale plotting surface to do Celnav, ENav, and DR's at reasonable intervals (say 1 hour which is the norm in the merchant marine). If we didn't have plotting sheets we would have to plot these positions on the only available charts for the area which are usually small scale ocean charts.  Those would be very difficult to plot on in increments under 4 hours.  They are never used where there is a possibility of hitting land.
    We typically don't use universal plotting sheets, but rather the pre-printed plotting sheets that are 3-digit charts like 923 etc.  They are Mercator projection with scribed latitudes and compass roses.  You turn them over when you use them in North or South Latitude.  Meridians are properly scribed, but unmarked so they can be used for any longitude that you wish.  They are also the full size of most charts and are much bigger than the universal sheets.
    Any photos I've posted of my Celnav work on the ship was plotted on these sheets.
    As soon as we get on a reasonably sized chart, we switch to that and leave the plotting sheet behind.
    In a message dated 11/14/2009 12:42:12 A.M. Eastern Standard Time, pmh099---.com writes:
    Looks like I'm getting into the habit of starting new threads lately...

    I remember reading that this is what the universal plotting charts are for.  Navigators can do their plotting on inexpensive paper without marking directly on precious nautical charts.  In the end, however, don't you have to translate your fixes onto a real chart anyway?  How do you not "ruin" a chart that way?  Aren't there tables with removable transparent surfaces on which you can mark and erase and below which you can affix a chart?

    On TV I saw vertical panels looking like plexiglass.  Can anybody describe what they are for and what the procedures are?

    Peter Hakel

    From: James N Wilson <jn.wilson{at}juno.com>
    To: navlist@fer3.com
    Sent: Fri, November 13, 2009 8:43:54 PM
    Subject: [NavList 10668] Re: AP terminology

    That reminds me of a story Ed Ripley told me, where he was on a power
    boat going up the California coast. He properly started plotting a DR
    track, whereupon the owner cried, "You're writing on my charts!" So he
    stopped. Later the radar went out, and they had no idea where they were.
    They  finally had to ask a fishing boat for that information. This, of
    course, was way before GPS.

    Jim Wilson
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