Navigation, in a nautical sense, is the act of directing a ship from one place to another, or the science of finding a way from one place to another. To achieve this a seafarer plots their position on charts, either paper or electronic after making calculations from using bearings, star sights or dead reckoning etc. Specialist instruments such as parallel rulers, dividers, sextants, compass etc. are all needed to accurately record their position. Astro navigation is not included in the training material. An aid to navigation is the buoyage system which is not universal. An introduction to navigation is provided to cover the basics in two parts. The first part covers the following subjects.