"Since J W Norie published the first edition of his Complete Set of Nautical Tables and Epitome of Practical Navigation in 1803, many changes to the tables have been necessary in both content and presentation. New tables have been included, obsolete ones deleted to conform with changing techniques of navigation, with the aim of improving the accuracy of the calculated position and reducing the tedium of the calculation. Since the commissioning of the Global Navigation Satellite System (GNSS), its proven accuracy and reliability in all weather conditions have resulted in confidence and almost unquestioning dependence on its ability to provide a vessel's position, course and speed. Its use is widespread but the marine environment is a hostile one and failure of electronic equipment or of the system itself is a possibility. No prudent seafarer would proceed on an ocean passage without a reliable navigational back-up. The Explanation is in the form of a detailed step-by-step description, by means of worked examples, of the different methods of performing navigational calculations using a scientific calculator and/or the tables. A number of esteemed editors have worked on Nories' Nautical Tables over the years and this edition includes new contributions from Francois Hugo. This edition now presents formulae in an appropriate format for direct entry to a scientific calculator. Because the possibility of navigation without even an appropriate calculator exists, the logarithms have been retained. * All the tables required for coastal and deep sea navigation are included * A simple uniform method of interpolation for all the trigonometrical tables is used * Certain tables and data are also included which are not readily available on board ship or are only used in the examination room."