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    Re: An interesting question
    From: Frank Reed
    Date: 2013 Oct 12, 12:20 -0700

    Lu, you wrote:
    "there was a great image of the moon directly aft of my stern. So I whipped out my sextant and used the waters as an AH. Reduced my sight and was disappointed to come out about 20 miles from my KP."

    I would bet you had some other coincidental error. This is a familiar trap: we try something tricky, make some error, then conclude the "tricky thing" doesn't work or is very difficult. I've done Jupiter sights off of still water in Fishers Island Sound with excellent results --less than 2' error.

    And I do agree with Gary that the quick solution if you have a sextant is a makeshift artificial horizon. There are other simple tricks on land, of course, which would even allow you to live without a sextant, especially at night when there are lots of stars near the zenith.

    Back to your original question, if you look at topo maps of the Great Plains, there's plenty of local relief. There are certainly areas where it would work, but the problem of determining which area is flat enough is probably not much different from the process of setting up an artificial horizon. Of course there are loads of lakes out there, the majority artificial. Get down low enough, and you have a good horizon on any but the smallest. And then there are dry lakes...


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