What do yellow over yellow lights signify?

Yellow over yellow lights indicate that a vessel is pushing another vessel ahead. This configuration serves as a visual signal to other vessels, informing them of the operational status of the pushing vessel. The use of colored lights is a critical part of navigation rules, as it helps maintain safety on the water by providing essential information regarding the movement and intentions of other vessels.

In maritime navigation, understanding these light signals is fundamental for assessing the actions of surrounding vessels. Yellow lights specifically denote actions relating to towing or pushing maneuvers, distinguishing them from other scenarios such as anchoring or vessels engaged in dredging, which have different signal requirements. Proper recognition of these signals helps ensure effective communication between vessels and prevents potential collisions or misunderstandings on the water.