NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Practical difficulties
From: Jeremy C
Date: 2011 May 13, 17:11 -0400
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.
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> 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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