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    Re: Welcome Aboard! New and returning...
    From: Magnus Sjoquist
    Date: 2011 Feb 7, 08:53 -0800

    Thank you for the welcome. I am new in the discussion group an will probably sit quite still in the boat just listening and learning from the expert group.

    Re horizon on sea surface covered with 4 feet of ice: On a cargo ship (where I have most of my navigational experience) where the height of eye may easily be 25 meters distance to horizon is around 10 nautical miles. At that distance 4 feet has no significance and can be neglected.
    If your height of eye is in the range where yachtsmen feel more at home (a couple of meters) you would have to be more careful, in particular watching out for ice ridges which could play a joke with you in the same manner as high swell. Why not checking with with an home made simple artificial horizon? Two (or more) observations with the horICEon and a couple with the artificial (i.e. a tin of water - double angle etc). Assuming you are not moving between the observations and that you take them more or less the same time, they should give you the same line of poition.

    Other risks with taking sights in icy waters are more related to difficulties that come with the temperatures in the air, how stable the atmosphere is right here and right now.

    Best Regards
    Magnus Sjoquist
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