A navigator's need includes a MAP, CHART, COMPASS, and sextant. A MAP is a two-dimensional representation of an area, usually drawn to scale. A CHART is a MAP that is used for navigation, showing the depths of water and other features of a coastline or river. A COMPASS is an instrument used for navigation that shows direction relative to the Earth's magnetic poles. A sextant is an instrument used for navigation that measures the angle between two visible objects, such as the sun and the horizon, to determine the navigator's position.