Marine Glossary

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Bowditch

Nickname for the NGA Pub. No. 9, entitled The American Practical Navigator, originally by Nathaniel Bowditch. The first edition appeared in 1802; the latest of some 90 editions was printed in 2002. The latest version is in one volume (blue cover); for several previous years it was issued in two volumes in a dark green cover.

Besides marine navigation, it includes excellent sections on marine weather, oceanography, and ice, with especially good coverage of hurricanes. First part (volume 1 in earlier editions) is principles and explanations; second part (original volume 2) is mostly tables and a glossary, along with valuable explanations of the tables. Part 1 includes atlases of the frequency and location of cyclones. It is a worthy goal for every mariner to know marine weather to the level of "Bowditch."

The government stopped printing this book, but several commercial companies have picked it up and sell reprints. At one time there was a paperback edition, but now only hard back. The full text is online. See www.starpath.com/navpubs.

It is called by some the Bible of navigation, comprising an epitome of navigation and navigational astronomy and providing tables for solution of navigational problems along with an extensive section on weather and oceanography. In earlier editions, volume two was mostly tables and their explanations.

Bowditch is a primary reference for USCG exam questions in all areas of navigation and weather. It includes a excellent summary of tropical cyclone statistics and a review of the world's major current systems. Some aspects editions prior to 2002 are outdated with regard to communications and other developments in electronic navigation, but even these older editions remain a thorough reference for traditional navigation and marine weather. Much of the material in the book, however, is so detailed that it can be overwhelming if one is new to the subject matter. The latest edition has improved on this in several areas.

Appendices include a list of physical constants (speed of sound in air and water, size of the earth, composition of the atmosphere) along with a thorough set of conversions between all units used in navigation and weather.

The latest edition has much less traditional navigation information than older editions. The 1938 edition covers most of what has been dropped and is often found used online.