What information is most important when passing near a lighthouse?

When passing near a lighthouse, understanding water depth is crucial because lighthouses often indicate safe passage routes and mark areas where navigational hazards might exist, such as shallow waters or rocks. Operators need to be aware of the water depth to avoid grounding their vessel, especially in areas where depths may change due to tides or other environmental factors.

While weather conditions, light signals, and traffic patterns also hold significance in navigation around a lighthouse, they do not directly affect the immediate requirement of ensuring a safe passage by maintaining appropriate water depth. Weather conditions can influence visibility and safety but knowing the water depth is fundamental to navigating safely near such structures. Light signals are vital for understanding navigational messages and warnings, but without proper attention to depth, a vessel risk could run aground, regardless of what signals are being conveyed. Similarly, while recognizing traffic patterns is essential for collision avoidance, it is secondary to ensuring that a vessel can safely navigate the water in which it is traveling.