Piloting or pilotage is the process of navigating on water or in the air using fixed points of reference on the sea or on land, usually with reference to a nautical chart or aeronautical chart to obtain a fix of the position of the vessel or aircraft with respect to a desired course or location. Horizontal fixes of position from known reference points may be obtained by sight or by radar. Vertical position may be obtained by depth sounder to determine depth of the water body below a vessel or by altimeter to determine an aircraft's altitude, from which its distance above the ground can be deduced. Piloting a vessel is usually practiced close to shore or on inland waterways. Pilotage of an aircraft is practiced under visual meteorological conditions for flight.
A navigator is the person on board a ship or aircraft responsible for its navigation. The navigator's primary responsibility is to be aware of ship or aircraft position at all times. Responsibilities include planning the journey, advising the ship's captain or aircraft commander of estimated timing to destinations while en route, and ensuring hazards are avoided. The navigator is in charge of maintaining the aircraft or ship's nautical charts, nautical publications, and navigational equipment, and they generally have responsibility for meteorological equipment and communications. With the advent of satellite navigation, the effort required to accurately determine one's position has decreased by orders of magnitude, so the entire field has experienced a revolutionary transition since the 1990s with traditional navigation tasks, like performing celestial navigation, being used less frequently. Using multiple independent position fix methods without solely relying on electronic systems subject to failure helps the navigator detect errors. Professional mariners are still proficient in traditional piloting and celestial navigation.
A GIS file format is a standard for encoding geographical information into a computer file, as a specialized type of file format for use in geographic information systems (GIS) and other geospatial applications. Since the 1970s, dozens of formats have been created based on various data models for various purposes. They have been created by government mapping agencies, GIS software vendors, standards bodies such as the Open Geospatial Consortium, informal user communities, and even individual developers.
Ilhéu das Rolas is an islet in the African island nation of São Tomé and Príncipe. The island lies on the Equator, off the southern tip of São Tomé Island, separated by Canal das Rolas. Its maximum elevation is 96 m (315 ft). Its population is 76. It is part of the Caué District. Access is only by ferry departing from Ponta Baleia on São Tomé Island. There is a lighthouse on the islet, built in 1929. Its focal height is 106 metres (348 ft) and its range is 12 nmi. The island is home to a small resort, the Pestana Equador.
The Vector Map (VMAP), also called Vector Smart Map, is a vector-based collection of geographic information system (GIS) data about Earth at various levels of detail. Level 0 (low resolution) coverage is global and entirely in the public domain. Level 1 (global coverage at medium resolution) is only partly in the public domain.
The American Practical Navigator, originally written by Nathaniel Bowditch, is an encyclopedia of navigation. It serves as a valuable handbook on oceanography and meteorology, and contains useful tables and a maritime glossary. In 1867 the copyright and plates were bought by the Hydrographic Office of the United States Navy. As of 2019 it is still published by the U.S. Government and is available free online from the National Geospatial-Intelligence Agency (NGA), the modern successor agency to the 19th Century Hydrographic Office. The publication is considered one of America's nautical institutions.
Sailing Directions are written directions that describe the routes to be taken by boats and ships during coastal navigation and port approaches. There are also products known as Sailing Directions, which are books written by various Hydrographic Offices throughout the world. They are known as Pilot Books, because they provide local knowledge of routes and landmarks, which would typically be provided by a local marine pilot. As such, they are used frequently by naval and government vessels, who are exempted from 'Compulsory Pilotage' in many ports.
A notice to mariners advises mariners of important matters affecting navigational safety, including new hydrographic information, changes in channels and aids to navigation, and other important data.
A Local Notice to Mariners is an authoritative instruction issued by a designated official, typically the harbormaster.
United States Coast Pilot is a ten-volume American navigation publication distributed yearly by the Office of Coast Survey, a part of the National Oceanic and Atmospheric Administration's National Ocean Service. The purpose of the publication is to supplement nautical charts of the waters of the United States.
Nautical publications is a technical term used in maritime circles describing a set of publications, either published by national governments or by commercial and professional organisations, for use in safe navigation of ships, boats, and similar vessels. Other publications might cover topics such as seamanship and cargo operations. In the UK, the United Kingdom Hydrographic Office, the Witherby Publishing Group and the Nautical Institute provide numerous navigational publications, including charts, publications on how to navigate and passage planning publications. In the US, publications are issued by the US government and US Coast Guard.
Distances Between Ports is a publication that lists the distances between major ports. Reciprocal distances between two ports may differ due to the different routes of currents and climatic conditions chosen. To reduce the number of listings needed, junction points along major routes are used to consolidate routes converging from different directions.
The Radio Navigational Aids publication contains a detailed list of selected worldwide radio stations that provide services to the mariner. The publication is divided into chapters according to the nature of the service provided by the radio stations. The services include Radio direction finder and Radar Stations; stations broadcasting navigational warnings, time signals or medical advice; communication traffic for distress, emergency and safety including the Global Maritime Distress Safety System (GMDSS) and long range navigational aids. It also contains chapters describing procedures of the AMVER System, and the interim emergency procedures and communication instructions to be followed by U.S merchant vessels in times of crisis. A new edition of Publication 117 is published annually. This publication is available in its entirety on the website and there are also database queries available for much of the data contained within.
The SRTM Water Body Data (SWBD) is a geographical dataset (2003) encoding high-resolution worldwide coastline outlines in a vector format, published by NASA and designed for use in geographic information systems and mapping applications. It was created by BAE Systems ADR for the US National Geospatial-Intelligence Agency (NGA) as a complementary product during editing of the digital elevation model database of the Shuttle Radar Topography Mission (SRTM). SWBD data covers the Earth's surface between 56° southern latitude and 60° northern latitude. It is distributed in ESRI shapefile format, divided into 12,229 files, each covering one 1°-by-1° tile of the Earth's surface.
The following tables compare general and technical information for a number of GIS vector file format. Please see the individual products' articles for further information. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs.
Ana Chaves Bay is a bay on the northeast coast of São Tomé Island in São Tomé and Príncipe. The capital city of São Tomé and its port are situated by the bay. It stretches from the Ponta Oque del Rei in the north to Ponta São Sebastião in the south. Forte de São Sebastião, now part of São Sebastião Museum, occupies Ponta São Sebastião. The port of São Tomé was built at the end of the 1950s on reclaimed land that extends 0.2 miles (0.32 km) north of Ponta São Sebastião; there is a 200 m quay at its north end, with a depth of 3 metres alongside. It is the main port of the country for solid goods; the port of Neves is the main point of entry for liquid fuels. The bay is generally shallow, offering anchorage for small vessels in depths of less than 5 metres (16 ft).
A sailor, seaman, mariner, or seafarer is a person who works aboard a watercraft as part of its crew, and may work in any one of a number of different fields that are related to the operation and maintenance of a ship.
Australian Pilot is a series of editions of Sailing Directions to navigators in Australian coastal waters.
