Piloting

Piloting or pilotage[1][2][3][4][5] is the process of navigating on water or in the air[1][2] 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.

In addition to providing descriptions of shipping channels and coastal profiles, they discuss weather, currents and other topics of interest to mariners.

Notable guides include a worldwide series of "Sailing Directions" by the United Kingdom Hydrographic Office (formerly by the British Admiralty) that includes, most notably, the English Channel, the Mediterranean Sea, the Red Sea and the Persian Gulf.

Measurement of depth and altitude allow vessels and aircraft navigators to confirm clear passage over obstructions.

[5] Flying at low altitudes and with sufficient visibility, aircraft pilots use nearby rivers, roads, railroad tracks and other visual references to establish their position.

The navigator compares the ground track with the navigational course for that leg of the intended route, in order to make a correction in "heading", the direction in which the craft is pointed to maintain its course in compensation for cross-currents of wind or water that may carry the craft off course.

[5] Where a channel is narrow, as in some harbor entrances and on some rivers, a system of beacons allows mariners to align pairs of daymarks, called "range markers", to form a "leading line" (British English)[5] or "range axis" (American English),[15] along which to navigate safely.