From Daniel Baxter:
Celestial Navigation Program. Master's Mate handles most of the calculations involved in this traditional, but still widely used method of navigation at sea. The features are organised using a simple tab system and are integrated to allow continuous progression to a final solution.
Interpolation of GHA and Declination values.
Correction of Sextant Altitude for Dip, Parallax, Refraction and Semi-Diameter.
Sight Reduction and the calculation of Latitude from a noon sight.