Which vessels at anchor are required to illuminate their decks?

Vessels at anchor are required to illuminate their decks to ensure visibility and safety on the water. This requirement applies to all vessels because proper illumination serves several critical purposes: it helps to prevent collisions by making the vessel more visible to other ships in the area, it allows crew members to proceed safely about the deck, and it provides an indication of the vessel's presence during periods of reduced visibility, such as at night or in poor weather conditions.

While specific regulations may emphasize certain vessel types, such as fishing, power-driven, or passenger vessels, the fundamental rule is that all vessels are obligated to provide adequate deck lighting when at anchor. This ensures a uniform standard of safety across the maritime environment, allowing for mutual awareness among various types of vessels navigating in proximity to one another.