1981 American Practical Navigator - Bowditch - Volume 2 - Paperback Book

This is the 1981 edition of Bowditch Volume II, Pub. No. 9 of the Defense Mapping Agency, in a print-on-demand paperback. The American Practical Navigator was divided into two volumes in 1975: Volume I carries the navigation text, and Volume II became the mariner’s ready reference for tables and calculations.

The 1981 revision added a glossary of marine navigation, a compact traverse table, two vertical-angle tables for piloting and a geographic range table. It also recomputed several tables for a new reference ellipsoid and refraction value. Throughout, the book gives the tables, formulas and worked instructions for computations in dead reckoning, piloting and celestial navigation, from conversion angles and distance calculations to sight reduction by the Ageton method and sextant altitude corrections.

The 1981 Volume II became the main reference for U.S. Coast Guard merchant mariner license exams, and many mariners still favor it, although the Coast Guard’s National Maritime Center switched to the current edition in 2022. It suits license candidates, instructors and celestial navigation students who want the classic tables in paperback.