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    Re: Taffrail log and an alternative
    From: Bernard Bishop
    Date: 2002 Jun 22, 09:58 -0500

    My first post to this list --and maybe I'm missing the
    point --but what's wrong with using an inexpensive GPS
    for SOG and other purposes, if you are really concerned
    or to back up other nav methods.
    
    Bernard Bishop
    
    "Trevor J. Kenchington" wrote:
    >
    > Many thanks to Bill Noyce and Arthur Pearson for their suggested
    > solutions to the non-electronic log problem. I'd still like an
    > instrument that would record distance run rather than instantaneous
    > speed, without needing batteries or an LCD. Still, I might have to force
    > myself to compromise on one or the other feature!
    >
    > As to Arthur's suggestion:
    >
    > > For bay crossings in the fog of Maine and Nova Scotia, a simple 30 foot
    > > chip log allows one to measure speed often enough and accurately enough
    > > to keep an accurate DR for several hours. Simply tie a bit of wood
    > > (weighted on one edge to be traditional and to minimize wind drift) on a
    > > length of light line, drop the chip overboard and time the number of
    > > seconds it takes for 30 feet of line to run out.  Divide 18 by the
    > > number of seconds to get nautical miles per hour, so 6 seconds indicates
    > > 3 knots. I measure speed and plot a DR every 15 minutes. Any inaccuracy
    > > in speed measurement is less important that whatever allowance one makes
    > > for current and lee way. This is all I have had on dozens of trips
    > > Downeast and back in Maine and combined with a good ear and a good nose
    > > you should be fine (keep the engine off so you can hear surf, gulls,
    > > barking dogs, etc.).
    >
    > Heaving a chip log is an attractive alternative but a bit awkward if
    > single-handed or with a crew that does not share a passion for such
    > eccentricities. If reduced to that level of technology, why not go one
    > step further and use a Dutchman's log?
    >
    > Trevor Kenchington
    >
    > --
    > Trevor J. Kenchington PhD                         Gadus{at}iStar.ca
    > Gadus Associates,                                 Office(902) 889-9250
    > R.R.#1, Musquodoboit Harbour,                     Fax   (902) 889-9251
    > Nova Scotia  B0J 2L0, CANADA                      Home  (902) 889-3555
    >
    >                      Science Serving the Fisheries
    >                       http://home.istar.ca/~gadus
    
    
    

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