The Nautical Almanac

US/UK Nautical Almanac

The Nautical Almanac is a standard for celestial marine navigation. It contains the following data tabulated at hourly intervals to a precision of 0.1 arcminute: the Greenwich hour angle and declination of the Sun, Moon, and navigational planets; the Greenwich hour angle of Aries; positions of the navigational stars; rise and set times of the Sun and Moon for a range of latitudes; and other data. Each edition also contains a sight reduction table; sight reduction formulas; and various correction tables for sight reduction.

In the United States the book is sold by the Government Publishing Office (Bookstore), and a number of marine supply companies. In the United Kingdom it is sold by the UK Hydrographic Office (UKHO).

The Astronomical Almanac Online! 2018
~ This is an official U.S. Navy website ~