You are holding position above Gallipolis Lock and Dam when you hear two long blasts of the horn from the lock. This indicates that you should __________.

Correct Answer: Option A — enter the riverward lock

In inland river navigation, lock signals are strictly regulated. Two long blasts from the lock master indicate that the vessel is cleared to enter the riverward lock chamber. Mariners must monitor these signals closely to ensure safe transit and avoid collisions or delays during locking operations.