Which vessel is the stand-on vessel when two vessels crossing in fog are NOT in sight of one another?

When two vessels are crossing in fog and are not in sight of one another, the situation involves understanding the responsibilities of vessels for safe navigation in restricted visibility. In such conditions, the Rules of the Road, specifically the International Regulations for Preventing Collisions at Sea (COLREGs), provide guidance.

In this scenario, neither vessel is designated as the stand-on vessel. Instead, both vessels are required to take action to avoid a collision, since they are not in sight of each other. The Rule that governs this situation emphasizes the need for vessels to maintain safety and avoid collisions when visibility is limited, thus both vessels must be prepared to take evasive action. The rules stipulate that in fog or other conditions of limited visibility, a vessel must make sound signals and maintain a proper lookout, and cannot simply rely on the concept of stand-on or give-way vessels as they would when visibility is clear.

This understanding of navigation in restricted visibility underscores the importance of mutual awareness and the need for vessels to take proactive measures to prevent collisions, rather than assuming roles based solely on their positions or sizes.