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The third and final step to finding a fix from celestial sights, the first two being the sextant sight and the sight reduction. The sight reduction leaves you with the four numbers in Workform, Box 6 (a-Lat, a-Lon, Zn, and a-value). These four numbers constitute the line of position (LOP) that this one sight has provided. This LOP is then plotted on a plotting sheet using dividers and parallel rulers or protractor. Your boat is located somewhere on this LOP.

The procedure is to plot a point at the assumed position (a-Lat, a-Lon). Then through this point draw the azimuth line in the direction of Zn. The LOP is perpendicular to this azimuth line, at a distance (in nautical miles) from the assumed position equal to the a-value. When the a-value is labeled "T," the LOP is on the side of the assumed position "Toward" the Zn direction, when a-value is labeled "A," it is on the other side of the assumed position, "Away" from the Zn direction. The perpendicular is best drawn using the cross lines printed on the protractor. See Assumed Position, Altitude Intercept (a-value), and Azimuth (Zn).

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