CelestNav™ for PalmOS

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CelestNavTM turns your PalmOS handheld into a full-featured calculator for celestial navigation.

CelestNavTM requires 204k of free memory, and runs on all PalmOS compatible systems version 3.0 and above, including Handspring Visors, Sony Clies, and Handera and TRG units. The free math library Mathlib, written by Rick Huebner, is required; a copy is included for your convenience.

Try it:

Download a free, fully functional, 10-day demo of CelestNavTM. Current version is 2.5, released October 12, 2002.

If you are already a CelestNavTM customer, this is also the file to download for your free version update.


Here's an online copy of the CelestNavTM tutorial.

Buy it:


Here are answers to some frequently asked questions.

Register your CD purchase

If you have purchased the CD version of CelestNavTM, register here for free upgrades.

CelestNavTM features:

  • computation of fix position from celestial observations.
  • perpetual nautical almanac for navigational stars, Moon, Sun, planets.
  • Mercator and Great Circle sailing computation.
  • computes range, height, sextant angle for lighthouses and other terrestrial objects.
  • twilight, rise, set, meridian passage computation.
  • automatic timing of sextant observations and adjustment to UTC.
  • handles backsights, non-standard atmospheric conditions, and more.
  • sight reduction screen with the functionality found in publications H.O. 229 and H.O. 249.
  • continuously updated dead reckoning position.
  • "finger-friendly" data entry screens for celestial observations, angles, dates, and times.
Look at some screen shots or read the tutorial.

Buy these essential books:

  • cover 2008 Nautical Almanac (Commercial edition)
  • cover One Hundred Problems in Celestial Navigation. A collection of problem sets, with answers. Each chapter follows a segment of a voyage; the voyages are in different parts of the world, and different vessels (including a dirigible!). Gray makes no assumptions about ho w you're working the problems.

Other navigation and astronomy software

These programs are written by others, but are very helpful in navigation.

Tide Tool
First-rate tide and current prediction tool. Covers the entire world except for the British Isles. Free!
Big Clock
Clock, timer, and stopwatch program. Also the easiest way to set the Palm's clock to the nearest second. Free!

Other handheld platforms

CelestNavTM requires PalmOS. It will not run on PocketPC platforms.

For a celestial navigation program and starchart program that does run on PocketPC, we recommend Pocket Stars, by Nomad Electronics.


Buy your PalmOS handheld organizer online.

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