Sea-chart, also known as nautical chart, nautical map, cartographic chart, or hydrographical chart, is a map designed for marine navigation. It is used to navigate the seas and indicate depths, currents, navigational hazards, and coastline features. These charts are important tools for sailors, fishermen, and sea transportation companies. Additionally, sea-charts are used for scientific purposes such as oceanography, marine geology, and marine biology. Other synonyms for sea-chart include sailing chart, marine map, ocean map, marine chart, and sea map. All of these terms refer to the same thing, a navigational map designed for marine use. They are essential tools for anyone setting sail on the high seas.