This volume provides the standardized astronomical data required for celestial navigation and timekeeping during the 1989 calendar year. The publication serves as an official reference tool for mariners, surveyors, and astronomers, compiling precise calculations of the positions of celestial bodies. It functions as a technical manual designed to facilitate the determination of position at sea through the observation of stars, planets, and the moon.

Experts recognize this publication as a standard, high-precision reference document for professional and recreational maritime navigation. Users frequently note the extreme density of the numerical data, which requires specific training in celestial navigation to interpret correctly.