What is the primary type of heading that we plot?

The primary type of heading that we plot is true heading. True heading refers to the direction in which the vessel is pointed relative to true north, which is based on the geographic North Pole. This is critical in navigation because it provides an accurate reference point for plotting courses on nautical charts and for understanding the vessel's position.

Using true heading helps ensure that navigational calculations are consistent, especially when planning routes over long distances, where variations such as magnetic declination become significant. True heading is crucial for navigating in conjunction with charts that use true north as their orientation.

While magnetic heading and compass heading are important for navigation as well, they are influenced by the Earth's magnetic field and the local magnetic variations, respectively. Deviation heading refers to the error introduced by the magnetic compass caused by nearby magnetic influences, which is why true heading is preferred for plotting purposes. Overall, true heading provides the most accurate and reliable information for safe navigation at sea.