What is a chart in navigational terms?

In navigational terms, a chart is primarily understood as a graphical representation of the spherical Earth. It provides essential information about various maritime features, including water depths, coastline configurations, navigational hazards, and the location of aids to navigation. This representation assists mariners in understanding the spatial relationship between different geographical features and planning their navigation accordingly.

Charts are designed to depict the Earth's surface in a way that allows for effective navigation, taking into account the curvature of the Earth and the projection methods used to represent three-dimensional features on a two-dimensional medium. This fundamental aspect of charts makes them crucial for safe and effective navigation at sea.

While options related to the ship's position, detailed planning of routes, and calculating distances are relevant to navigation, they do not capture the core function and definition of a chart itself, which is fundamentally about visualizing and interpreting the geography of the environment in which navigation takes place.