What should vessels do when operating in restricted visibility?

When operating in restricted visibility, vessels must maintain a safe speed to ensure they can take effective action to avoid collisions. This rule emphasizes the importance of being able to stop safely within the distance that is visible. Maintaining a safe speed allows a vessel to navigate cautiously and react appropriately to unexpected obstacles or other vessels that may emerge suddenly in low visibility conditions.

In these situations, the vessel's ability to assess distance, speed, and the actions of nearby vessels is severely impaired, so slowing down ensures that the vessel can maneuver without endangering itself or others. Additionally, a safe speed provides the time needed to employ sound navigational practices, such as using sound signals and radar, to enhance awareness of the surrounding environment.

Speeding up would only increase the risk of collision or grounding due to the reduced reaction time in limited visibility. Switching off lights would hinder visibility rather than assist navigation. Changing course frequently can create confusion and potentially lead to unsafe situations with other nearby vessels. Hence, maintaining a safe speed is the most effective strategy for ensuring safety in these conditions.