| Bowditch Online: Navigation course containing 38 chapters covering charts, radar, astronomy, and regulations. Glossary. Archives for the navigation mailing list. |
| Celestial Navigation Data: Astronomical information necessary to plot navigational lines of position from observations of the altitudes of celestial bodies from the U.S. Naval Observatory. |
| Digital Navigation Publications: Downloadable publications from the National Imagery and Mapping Agency including The American Practical Navigator and Radio Navigational Aids. |
| Navigate!: A free online course in basic coastal navigation. |
| Navigation Information Connection: Links and photos associated with the U.S. Inland Waterway System. Includes real time location and queue lists of towboats and barges operating on U.S. inland waterways. |
| Sailing Issues: Navigation Course: Contains nine chapters covering piloting, plotting, navigation aids, and tides. Related equations and tables. |
| The Complete On-Board Celestial Navigator: About a reference book for navigation at sea. Includes table of contents and purchasing information. |
Classical
