Navigation aids are tools used by sailors and navigators to help them find their way. RADARS, a 6 letter word, is an acronym for Radio Detection and Ranging, which is a system that uses radio waves to detect objects and measure distances. CHARTS, also a 6 letter word, are maps used to plot a course and navigate the seas. SEXTANTS, an 8 letter word, are instruments used to measure the angle between two visible objects, such as the sun and the horizon, to determine a ship's position. Finally, STARS, a 5 letter word, are celestial bodies used to help sailors orient themselves and determine their location.