What does 'Gain' refer to in the context of radar navigation?

In radar navigation, 'Gain' refers to the amplification of the radar signal's return. By adjusting the gain, a navigator can enhance the strength of the returns from objects within the radar's range, which allows for better visibility of weaker signals or distant objects. This is particularly important in varying weather conditions or when navigating in areas with potential clutter, as it improves the accuracy and reliability of the radar display. Setting the gain properly ensures that all relevant targets are detected and accurately represented on the radar screen, thereby enhancing situational awareness and safety at sea.

Other answers focus on different aspects of navigation or ship performance, which, while important, do not relate to the concept of 'Gain' within radar systems. For instance, adjusting the ship's speed pertains to maneuvering and velocity control, measuring directional accuracy deals with navigation reliability, and calculating distance covered relates to distance measurement, none of which involve the amplification of radar signals.