Question 390Navigation General70% to pass
You are upbound approaching a lock and dam and see two green lights in a vertical line. This indicates _______________.
AI Explanation
The correct answer is A) the downstream end of an intermediate wall.
The presence of two green lights in a vertical line indicates the downstream end of an intermediate wall within the lock. This configuration helps mariners identify the navigable passage through the lock structure. The other answer choices are incorrect because they do not accurately describe the meaning of this specific light configuration.
B is incorrect as it refers to the navigable pass of a fixed weir dam, which is a different type of waterway structure. C is incorrect as two green lights do not indicate a double lockage in progress. D is incorrect as the lights do not mark the downstream end of the land wall, which is a different part of the lock system.
Related Questions
#388 The channel under a bridge is marked with lights of the lateral system. The centerline of the channel shall be marked on the bridge by _______________.#389 A bridge over a navigable waterway is being repaired. There is a traveler platform under the bridge's deck that significantly reduces the vertical clearance. If required by the CG district commander, how will this be indicated at night? #391 You are downbound approaching a lock and see 3 green lights in a vertical line. This indicates _______________.#392 Restricted areas at locks and dams are indicated by _______________.#393 Permission to enter the riverward chamber of twin locks is given by the lockmaster and consists of which sound signal?