The Nautical Almanac is carried on every ship within the Royal Navy and on many sea-going vessels around the world. It is at the core of celestial navigational training courses worldwide. Carriage of The Nautical Almanac is required in either paper or digital format, under Regulation 19.2.1.4 of SOLAS Chapter V.

This annual publication includes:

• Tabulations of the Sun, Moon, navigational planets and stars to help determine positions at sea when using a sextant
• Times of sunrise, sunset, twilights, moonrise and moonset, calendarial information, phases of the Moon and eclipses of the Sun and Moon to help bridge crews plan observations
• Interpolation and altitude correction tables, pole star tables and diagrams, and notes for the identification of stars and planets
• Information on standard times for countries around the world
• A concise set of sight reduction tables and sight reduction forms
• A six-page supplement of polar astronomical phenomena including semi durations of sunlight, civil twilight and moonlight included in the publication at the request of the Royal Navy