Ibn Majid wrote sailing manuals to assist other travellers. His most famous book, written in 1490, was an encyclopaedia of navigational information called 'Kitab al-Fawa'id fi Usul 'ilm al-bahr wa al-qawa'id', or 'Book of Useful Information on the Principles and Rules of Navigation'. In it he dealt with the fundamentals of sailing and how to navigate using the stars.