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    Re: Practical difficulties
    From: Jeremy C
    Date: 2011 May 13, 17:11 -0400
    Heave and surge are the last two.  Heave is bodily motion of the vessel up and down and surge is bodily motion in the direction of travel.
     
    In a message dated 5/13/2011 1:58:32 P.M. Eastern Daylight Time, mbiew@comcast.net writes:
    Patrick,

    For my edification, why do your refer to six degrees of freedom for boat motion rather than three?  I can imagine roll, pitch and yaw.  I guess one could add bobbing up and down.  T

    Thanks for the report; I like sea stories.

    Fred

    On Fri, May 13, 2011 at 12:46 PM, Patrick Goold <goold@vwc.edu> wrote:

    > (4)        The next day the sky was clear all day.  But now we were on a broad reach with a steep and substantial quartering swell.  The boat was moving quickly through all six degrees of freedom.  I am not especially prone to seasickness but this kind of tack is the one most likely to bring it on.  Even if I have had a few days to get my sea legs (which I hadn't in this case), when the boat is yawing, swaying and surging in addition to pitching, rolling and heaving, I need to keep one eye on the horizon or go green.  The sextant never left the case.  Even had I taken a full set of sights, reducing and plotting them would have been beyond me.
    >

    > These were not storm conditions.  It was a rather typical spring day on the Chesapeake Bay.  The wind was NE at 15 knots.  The swell was no more than three or four feet but short and steep. 
    >
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    > Patrick
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