Sky and Sea Software

- Arturo and Raffaele Chiesa - Celestial Navigation, Elementary Astronomy, Piloting



In this site you can find a complete BOOK of Celestial Navigation, Elementary Astronomy and Piloting supported by an OPERATIVE SOFTWARE with 27 operative programs.


You can DOWNLOAD FOR FREE all the material in this site as the Authors - Arturo and Raffaele Chiesa - are pleased to spread their work to all people who are passionate on these topics.


The book embodies three parts:

  • Celestial Navigation
  • Elementary Astronomy
  • Piloting



The outstanding feature in CELESTIAL NAVIGATION is a new method to immediately obtain a fix (vessel position) by entering the sequences  h-t  of the sextant altitudes and chronometer time readings of at least two celestial bodies in a programmed computer. No tables as HO tables or similar, no graphical construction on a nautical chart. The computer immediately provides the fix and optionally provides course, distance and time to reach a destination point.

The procedure applies to any kind of celestial body: Sun, Moon, planets, stars.


A set of ASTRONAMICAL PROGRAMS offers wide fields of application to astronomy hobbyists:

  • Position of celestial bodies for any date, time and place
  • Times for an altitude or an azimuth
  • Solar System
  • Diurnal arcs
  • Image of the sky
  • Diagrams of time lines of rising, meridian passage and setting of any celestial body
  • Motions of the constellations
  • Identification of stars and constellations

Validity of the data: two centuries from January 1st  1900 to December 31  2100.




  • Great circle routes and rhumb line routes
  • Plotting point by point a great circle route
  • Crossing point of the route for any longitude
  • Great Distances: route run along  rhumb line legs
  • Plotting the grid of a Mercator nautical chart


The programs of the three parts are tightly connected in many examples worked out in the book. But each part also cover kinds of application specific of  that single part.




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