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    Re: Range from calculated dip of the shore horizon
    From: Bob Crawley
    Date: 2018 Oct 5, 07:27 -0700

    Yes Robert I have tried it. I have a Monocular with compass and MIL graduations so figured that this would be useful for quickly assessing the distance off from ships (we have a busy port here). It turns out that if I'm near enough to get a meaningful measurement (not easy with a Monocular on a yacht) then I'm far too close, It does work quite well from the cliff top at about 35m height but I'm not in much danger of collision there. My sextant would be much better but it does not fit in my pocket.

    On a related topic I created a circular scale wrapped around the monocular so that I could read off distances without calculation. This progressed to objects below the visible horizon which got me into the history of the errors in the formula given in Bowditch.

    It's all very interesting but too hard to get a reliable reading when jiggling up and down. A stabilised monocular like my Canon binoculars would be nice but it seems impossible to get all the features one wants in a single gizmo.


    Bob Crawley

    52N 001E

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