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    Re: Wind & Current Navigation
    From: George Huxtable
    Date: 2003 Apr 18, 00:08 +0100

    In replying to a question from Dan Allen, I said-
    >>Is that good enough to satisfy Dan, or does he wish to get more fundamental?
    and he replied-
    >More fundamentals!  Teach us hydrophysics!
    Well, teaching hydrophysics is something I must decline with regret.
    1. It's not my subject. What I have explained to the list is pretty near
    the sum total of all I know about hydrodynamics. And I've cogged that
    mostly from "Sailing Theory and Practice" by C A Marchaj (Adlard Coles,
    London, 1964). I recommend that book to any searcher after wisdom about the
    interactions between boats, wind, and water. Not that it's free of faults:
    there are some significant areas of confusion. But it's the best text that
    I know of, about a big topic.
    2. First things first. Most important item on my agenda is the long-delayed
    scrub-off and antifouling of my boat Christina, done with her leaning
    against a wall, between tides. Poole has a very low tidal range, which is
    convenient in many respects, but not for that job. It's only at the top of
    springs that there's enough range to uncover her 4-foot draught keel. This
    weekend is that tide, and my wife and I will be spending our Easter
    grovelling about in the muck.
    3. I haven't forgotten (though you might not believe it) that I still owe
    the list the long-promised concluding part or parts of my saga about
    lunars. That comes first, and Dan will have to find an appropriate guru to
    teach him hydrodynamics.
    In the same thread, Dave Weilacher asked-
    >You may have just sorted out a nautical saying that I have often wondered
    >about the arithmetic of.
    >"Twice the wind has eight times the force"
    >This is probably correct if it is "Twice the wind has eight times the power".
    >Do I understand this right?
    I haven't heard that expression, but put the way Dave has done, I think it
    would then be correct
    contact George Huxtable by email at george@huxtable.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.

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