Celestial navigation exploits the principle that every measurement taken with a sextant converts to a line of position on a chart, the intersections of two or more such lines providing a position fix.


Our offline compatible app CelNav 360 graphically streamlines the celestial fix workflow, turning your device into a practical accessory to a sextant.




1 - Set Assumed Position

Tap AP in the action bar

2 - Sight Preparation

Tap MODE in the action bar to toggle a view of the computed horizon at the assumed position

3 - Add a Sight

Open the Sights Table by tapping the icon at the bottom right of the screen.

Tap the sextant icon and select from Sun/Star/Planet/Moon

The dip correction at the bottom left of the dialog may be adjusted by tapping on it

4 - Lines of Position

The line of position derived from each sight is represented in the table by its intercept and azimuth.

Tap MODE in the action bar to toggle a graphical view of all the lines of position in the table

5 - Sight Reduction Detail

Select a table entry and tap altitude