In naval terminology a Plot is a graphic display that shows all collated data from a ship's on-board sensors i.e. radar, sonar and EW systems. They also displayed information from external sources i.e. other vessel or aircraft reports. There are four different types of plot, each with varying capabilities i.e. range, depending on their role;
Air Plot: Used for tracking air contacts i.e. planes and EW information
Surface Plot: Used for tracking contacts on the surface of the water i.e. other ships. It can also perform a variety of roles such as;
Providing a trace of a ship's own course and speed over time
Plotting the position of a man overboard
Can be used in naval gunfire support missions to plot unidentified contacts and keep track of friendly forces
It also plays an important part in anti-submarine warfare operations and using Torpedoes
Sub-Surface Plot: Used for tracking contacts below the surface of the water i.e. submarines
General Operations Plot: Used for tracking shipping on a large scale chart. Was also used to display exercise boundaries, airlanes and other significant features of maritime interest. In the Royal Australian Navy, the scale used was generally 5 or 10 miles (8.0 or 16.1 km) per 1 inch (25 mm).
