2019 American Practical Navigator - Bowditch - Volume 2 - Paperback Book

Volume II of the 2019 American Practical Navigator (“Bowditch,” Pub. No. 9), published by the National Geospatial-Intelligence Agency, is the tables-and-calculations companion to the Volume I text. This 2019 edition continues the two-volume format NGA restored in the previous edition, which gave the tables and calculations a book of their own.

Part 1 holds 36 tables: mathematical (logarithms, trigonometric functions, traverse tables), cartographic (chart scales, meridional parts, length of a degree), piloting (unit conversions, measured mile, speed-time-distance, distance of the horizon, geographic range, distance by vertical angle), celestial (offsets, amplitudes, altitude factors, time zones, altitude corrections) and meteorological (true wind, barometer corrections, relative humidity, dew point). Part 2, Mathematics for Navigation, covers mathematics, interpolation, navigational errors, calculations and conversions, and compass conversions and error. Appendices on world sailing ship routes, haversine tables and compass points are followed by a glossary of marine navigation and a glossary of abbreviations and acronyms.

NGA has since issued a 2024 Volume II that it describes as almost a complete rewrite. This 2019 edition keeps the tables, formulas and glossary as they stood before that revision.