/ 
Every week, Bateaux.com will ask you a question about the boating license. This is a chance to test your knowledge or even discover new topics. This week, we?re covering the topic of vessel lights.
What do these three lights at night represent?
At night, two red lights stacked one above the other indicate that a vessel is unable to maneuver. These red lights must be visible across the entire 360° horizon. During the day, these lights are replaced by two stacked balls.
A vessel that has lost control of its maneuvering is one that, due to exceptional circumstances, is no longer able to maneuver. It is therefore no longer able to comply with the RIPAM rules (rudder failure, engine problems, being forced to heave to in bad weather, etc.). This concept differs from that of a vessel with restricted maneuverability. The latter is still capable of navigating but must not leave a channel?for example, due to its draft?or is in the process of dredging.
In our example, we can also see its green light. This means that the vessel not in control of its maneuver is moving forward (it has a drift) and that we can see its starboard bow. If the vessel had no drift, it would have to turn off its navigation lights (so we wouldn?t see the green light).
