Plot

To chart or mark a course on a nautical chart or map. A marked course or route on a nautical chart, or the act of determining a vessel’s position and intended path.

Plotting is a fundamental aspect of maritime navigation, involving the precise marking of a vessel’s current position and its intended course on a nautical chart. This process is crucial for ensuring safe passage, especially when navigating through unfamiliar waters or areas with potential hazards such as reefs, shoals, or other obstructions. The navigator uses various tools, including parallel rulers, dividers, and compasses, to accurately plot the course. 

The plot is typically based on a combination of dead reckoning (estimating the vessel’s position based on speed, time, and direction), celestial navigation (using the stars, sun, and planets), and modern electronic systems such as GPS. The plotted course helps the crew maintain situational awareness, allowing them to anticipate changes in the environment, such as tides, currents, and wind patterns, which can affect the vessel’s trajectory. 

In traditional navigation, the plot is updated regularly to account for any deviations from the planned course, ensuring that the vessel remains on track. This process is particularly important during long voyages or when navigating in poor visibility conditions, where reliance on visual landmarks is limited.