Coast Guard Exams
Question 461Navigation General70% to pass

On an Army Corps of Engineers navigation map, each mile A.H.P. on the Lower Mississippi River is marked by a _______________.

AI Explanation
The correct answer is D) black dot. On Army Corps of Engineers navigation maps for the Lower Mississippi River, each mile Above Head of Passes (A.H.P.) is marked by a black dot on the map. This is the standard convention used to denote mileage markers on these navigation charts. The other answer choices are incorrect because: A) navigation lights are physical markers on the river, not map symbols; B) dashed red lines are not used to mark mileage on these maps; and C) while the maps do show numerical mileage, the mileage is not indicated by a number at each individual mile marker.

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