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    Re: Calibrating the Practice Bubble Horizon with a sea horizon
    From: Sean C
    Date: 2014 Mar 17, 14:35 -0700

    "If my reasoning is on track, the reading I got is not the final bubble correction. If I were to use this correction to make an observation of a celestial body, I would still need to include dip height-of-eye in the sight reduction as my initial 5’ correction was for the visible horizon." -Bill

    I think that's what the instructions say:

    "Place all of the horizon sunshades so as to block the view of the nautical horizon through the horizon mirror. Put the bubble alongside the hairline in the normal manner. Bring the natural horizon as reflected by the index mirror to the hairline by moving the micrometer drum. Next, find the dip correction from table A2 of the Nautical Almanac for your height of eye. Now carefully turn the drum to increase the sextant reading by this amount. The resulting reading is the error which you may subtract as a correction (BC) to future readings."

    Sounds essentially the same to me.

    -Sean C.
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