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Celestial Navigation Data - http://aa.usno.navy.mil/data/docs/celnavtable.php
Astronomical information necessary to plot navigational lines of position from observations of the altitudes of celestial bodies from the U.S. Naval Observatory. |
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Navigation Information Connection - http://www2.mvr.usace.army.mil/NIC2/default.cfm
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. |
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Bowditch Online - http://www.irbs.com/bowditch/
Navigation course containing 38 chapters covering charts, radar, astronomy, and regulations. Glossary. Archives for the navigation mailing list. |
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Sailing Issues: Navigation Course - http://www.sailingissues.com/navcourse0.html
Contains nine chapters covering piloting, plotting, navigation aids, and tides. Related equations and tables. |
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Digital Navigation Publications - http://164.214.12.145/pubs/
Downloadable publications from the National Imagery and Mapping Agency including The American Practical Navigator and Radio Navigational Aids. |