Question 187Navigation General

The correct answer is B) Red lights. When a navigational channel passes under a fixed bridge, the edges of the channel are marked on the bridge with red lights. This is in accordance with the U.S. Aids to Navigation System, which specifies that red lights must be used to mark the limits of the navigable channel under a fixed bridge. The red lights help vessels identify the safe passage through the bridge opening. The other answer choices are incorrect because: A) The lights would not be green on the right descending bank (RDB), as green lights are used to mark the right side of the channel. C) Yellow lights are not used for this purpose. D) Three white lights in a vertical line are not the standard marking for a fixed bridge over a navigational channel.