Pilotage
Encyclopedia
Pilotage is the use of fixed visual references on the ground or sea by means of sight or radar to guide oneself to a destination, sometimes with the help of a map
or nautical chart
. People use pilotage for activities such as guiding vessels and aircraft
, hiking
and Scuba diving
. When visual references are not available, it is necessary to use an alternative method of navigation
such as dead reckoning
(typically with a compass
), radio navigation
, and satellite navigation (such as GPS
).
, aeronautical chart
or nautical chart
. Many nautical and aeronautical disasters have resulted from the pilot incorrectly identifying visual references.
Poor visibility
may affect safe navigation by obscuring the natural features used by pilots in an area. In such situations, pilots use navigational aids such as radar and the GPS to determine position and monitor their passage.
During the day:
At night:
While not strictly a "visual feature," depth, measured by electronic means or manually (with a lead line), can also be an important element of pilotage.
Pilotage is frequently combined with navigation
techniques such as dead reckoning
. When a pilot at a known location cannot see the next visual reference on the route to a destination, he or she can use dead reckoning to get closer to the next reference point. This is the most common form of VFR
navigation.
Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
or nautical chart
Nautical chart
A nautical chart is a graphic representation of a maritime area and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land , natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids...
. People use pilotage for activities such as guiding vessels and aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, hiking
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
and Scuba diving
Scuba diving
Scuba diving is a form of underwater diving in which a diver uses a scuba set to breathe underwater....
. When visual references are not available, it is necessary to use an alternative method of navigation
Navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
such as dead reckoning
Dead reckoning
In navigation, dead reckoning is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course...
(typically with a compass
Compass
A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...
), radio navigation
Radio navigation
Radio navigation or radionavigation is the application of radio frequencies to determine a position on the Earth. Like radiolocation, it is a type of radiodetermination.The basic principles are measurements from/to electric beacons, especially...
, and satellite navigation (such as GPS
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
).
Difficulties
Pilotage depends on the pilot being able to recognise the visual references in order to make use of them. The pilot must either be familiar with those visual references or be able to discover them from a mapMap
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
, aeronautical chart
Aeronautical chart
An aeronautical chart is a map designed to assist in navigation of aircraft, much as nautical charts do for watercraft, or a roadmap for drivers...
or nautical chart
Nautical chart
A nautical chart is a graphic representation of a maritime area and adjacent coastal regions. Depending on the scale of the chart, it may show depths of water and heights of land , natural features of the seabed, details of the coastline, navigational hazards, locations of natural and man-made aids...
. Many nautical and aeronautical disasters have resulted from the pilot incorrectly identifying visual references.
Poor visibility
Visibility
In meteorology, visibility is a measure of the distance at which an object or light can be clearly discerned. It is reported within surface weather observations and METAR code either in meters or statute miles, depending upon the country. Visibility affects all forms of traffic: roads, sailing...
may affect safe navigation by obscuring the natural features used by pilots in an area. In such situations, pilots use navigational aids such as radar and the GPS to determine position and monitor their passage.
Visual features
Common types of visual reference point used for pilotage:During the day:
- Natural features: MountainMountainImage:Himalaya_annotated.jpg|thumb|right|The Himalayan mountain range with Mount Everestrect 58 14 160 49 Chomo Lonzorect 200 28 335 52 Makalurect 378 24 566 45 Mount Everestrect 188 581 920 656 Tibetan Plateaurect 250 406 340 427 Rong River...
s, hillHillA hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit A hill is a landform that extends above the surrounding terrain. Hills...
s, lakeLakeA lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
s, riverRiverA river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
s and coastal features such as cliffCliffIn geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...
s, rockRock (geology)In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
s and beachBeachA beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...
es - Man made nautical features: sea markSea markA sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage aid which identifies the approximate position of a maritime channel, hazard and administrative area to allow boats, ships and seaplanes to navigate safely....
s, land marksDaymarkA daymark or a day marker is a structure such as a tower constructed on land as an aid to navigation by sailors. While similar in concept to a lighthouse, a daymark does not have a light and so is usually only visible during daylight hours...
and radioRadioRadio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
aerials - Man made land features: AirportAirportAn airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...
s, citiesCityA city is a relatively large and permanent settlement. Although there is no agreement on how a city is distinguished from a town within general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.For example, in the U.S...
, damDamA dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
s and highwayHighwayA highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...
s
At night:
- Man made nautical features: LighthouseLighthouseA lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....
s, lightvesselLightvesselA lightvessel, or lightship, is a ship which acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction...
s and sea markSea markA sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage aid which identifies the approximate position of a maritime channel, hazard and administrative area to allow boats, ships and seaplanes to navigate safely....
s with lights - Man made land features: Airports, illuminated towers and buildings
While not strictly a "visual feature," depth, measured by electronic means or manually (with a lead line), can also be an important element of pilotage.
Pilotage is frequently combined with navigation
Navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
techniques such as dead reckoning
Dead reckoning
In navigation, dead reckoning is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course...
. When a pilot at a known location cannot see the next visual reference on the route to a destination, he or she can use dead reckoning to get closer to the next reference point. This is the most common form of VFR
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
navigation.