Your vessel is entering port and you have steadied up on a range, dead ahead, in line with your keel. After a few minutes the range, still dead ahead, appears as shown in illustration D047NG below. Which action should you take?

Correct Answer: Option B — Alter heading to the left

When a range ahead shows the upper mark displaced to the left, the vessel has drifted to the right of the intended track. Altering heading to the left corrects the lateral displacement and brings the range back into line.