What does "pilotage" refer to in navigation?

Pilotage refers to the method of navigation that relies on visible landmarks and features on the ground or water to determine a pilot's position and course. This technique is particularly effective in areas where the topography allows for clear identification of landmarks, such as cities, rivers, and mountain ranges. By recognizing these features, pilots can adjust their flight path accordingly without the need for electronic instruments or complex calculations.

The other options describe different navigation methods. Using instruments for navigation pertains to techniques like IFR (Instrument Flight Rules) flying, while calculating flight paths with weather data often involves the use of calculations and forecasts to optimize a route based on current conditions. Navigating through calculated altitudes emphasizes altitude management rather than visual navigation. In contrast, pilotage emphasizes direct visual cues and is a fundamental aspect of VFR (Visual Flight Rules) navigation.