What does a vessel need to show to avoid collision in restricted visibility?

In restricted visibility, it is essential for a vessel to exhibit sufficient navigation lights to ensure that it remains visible to other vessels and can effectively communicate its presence and intentions. According to the COLREGs (International Regulations for Preventing Collisions at Sea), appropriate navigation lights are critical in helping vessels determine each other's course and bearing, thereby preventing potential collisions.

Displaying navigation lights provides vital information about the vessel's type, activity, and direction of travel. This is particularly important in conditions where visibility is compromised, such as during fog, heavy rain, or darkness. By showing these lights, a vessel can maintain safe passage and facilitate the necessary situational awareness for other vessels in the vicinity.

While sound signals can be used in restricted visibility, they are not a substitute for navigation lights; instead, they serve as an additional precautionary measure. High-intensity lights and no lights or signals are not appropriate for navigating in restricted visibility and do not enhance safety as effectively as having the correct navigation lights displayed.