Editing Nautical chart (section)

=== Pilotage information ===
[[File:NOAA chart 25664 1976 detail.png|right|thumb|Detail of a United States NOAA chart, showing a harbour area]]

The chart uses symbols to provide [[pilotage]] information about the nature and position of features useful to navigators, such as sea bed information, [[sea mark]], and landmarks. Some symbols describe the sea bed with information such as its depth, materials as well as possible [[navigational hazards]] such as [[shipwreck]]s. Other symbols show the position and characteristics of [[navigational aid]]s such as [[buoy]]s, [[light characteristic|lights]], [[lighthouse]]s, coastal and land features and structures that are useful for [[position fixing]]. The abbreviation "ED" is commonly used to label geographic locations whose existence is doubtful.

Colours distinguish between human-made features, dry land, sea bed that dries with the tide, and seabed that is permanently [[underwater]] and indicate water depth.