What does the term "visibility" refer to in navigation?

In navigation, the term "visibility" is primarily understood as the ability to see surrounding vessels and hazards. This aspect is crucial for safe navigation, especially in conditions where visual references are necessary for determining the position of other ships, navigational aids, and potential dangers. Good visibility allows a navigator to make informed decisions and maintain situational awareness, reducing the likelihood of collisions and grounding.

Clarity of the horizon, brightness of the ship's lights, and the distance of land from open water, while relevant in various contexts, do not encompass the broader navigational implications of "visibility." These factors may influence visibility under specific conditions but do not represent its primary definition in navigation. In essence, effective navigation hinges on the navigator's capability to identify threats and assess the surrounding maritime environment, underscoring why the capacity to see vessels and hazards is paramount.