When must a vessel display a lantern at night?

A vessel must display a lantern at night when it is anchored or moored in navigable waters to ensure visibility and safety for other boaters. This requirement is crucial because it helps prevent collisions by signaling to approaching vessels that the anchored boat is present, reducing the risk of accidents in the dark. The light serves as a warning to others navigating the area, especially in busy waterways where visibility may be compromised.

The other situations listed, while they may also require certain lights to be displayed, are typically governed by different rules. For example, moving through narrow channels and approaching other vessels involves specific navigation lights that indicate the vessel's status and intentions, whereas fishing at night might have its own light requirements for attracting fish or signaling the boat's position. However, the clear need to display a lantern when anchored or moored is centered around safety and visibility, making it a key regulation for nighttime boating.