This website contains celestial navigation and sailing resources:

Software titles

Celestial Navigation calculations with perpetual almanac, star finder, lines of position, astronomical position, meridian passage.
Windows desktop version includes VRTool charting and GPS/NMEA interface

Navigator for Windows

App Store

Download and install

Also available as a CD ROM
with printed manual,
from Celestaire Inc

for iOS
App Store
Purchase from Apple App Store

Navigator methods

Using Navigator

Navigator Forum


This virtual sextant app uses the phone sensors and camera to read the altitude of celestial objects.
Turn your phone into a simple marine sextant for celnav training.
On screen, real time display of stars and planets. Great for celestial object identification.
Free app
Download for iOS and Android

App Store
App Store

Worldwide sailing simulation using physics. Sail the world with real time winds. Embedded VRTool for route planing. Earn OPYCoins.
Free sailing game. Available for Windows, iOS and Android.
Free app
Download for Windows
App Store

Download for iOS and Android

App Store

App Store

More OPYC information

OPYC Forum

Charting app with tools and numerical calculations for sailors. With NOAA GFS wind forecasts (from our own server), track planning, weather routing, GSHHS charts, GPS interface, Polar chart creation and edition, NMEA talker. Integration with Navigator and VRTool desktop.
Free app
Download for Windows
App Store

Download for iOS and Android

App Store

App Store

VRTool wiki

Online web services

your guide to the navigation sky

The Online Nautical Almanac

- perpetual almanac data
- traditional NA layout

DIY sextant projects - Built your own instrument

Foamboard Octant
Large octant made with
foamboard and Lego pieces.
Also available as Instructable

Small sextant built with a CD Box

Teleobjective and Sun filter for you phone. To be used with CamSextant app. Also avalable as an * Instructable


Precision phone frame for CamSextant app. Also avalable as an Instructable

xtant project

Medium sized octant with plastic frame

Nautical Almanacs in PDF format

2023 Navigator Nautical Almanac new
2022 Navigator Nautical Almanac
2021 Navigator Nautical Almanac
also available: 2020 , 2008, 2002

Celestial navigation texts

Celestial navigation introduction - translations available:
English Français Português Español

Identification of stars and planets

Object distances and Lunar calculation

the meridian passage

Navigator calculation methods

Simple meridian passage calculation

Navigator in the ARC regatta

How to find your position using Navigator

 program screen shots

 Chart library - Vector charts. Links for raster chart images on the Internet.

 User Gallery Sextants, octants and document translations posted by users


Privacy policy
Terms of service

Contact the author or give feedback

ęCopr 92-2012
Omar F. Reis - All rights reserved