Question 1859Navigation General

The correct answer is A) an eddy working along the lower guide wall. Backlash below a lock refers to the eddy or reverse current that forms along the lower guide wall of the lock chamber as the water level drops after a vessel exits the lock. This eddy or current setting back into the lock is known as the backlash, and it can affect the maneuvering of a vessel exiting the lock. The other options are incorrect because they do not accurately describe the definition of backlash below a lock. Option B refers to a current setting into the lock chamber, which is not the specific definition of backlash. Options C and D describe currents setting the vessel on the wall or in a counter-clockwise direction, which are not the defining characteristics of backlash.