Coast Guard Exams
Question 4318Deck General70% to pass

Air gap is the vertical distance between the bottom of the hull and the _______________.

AI Explanation
The correct answer is A) still water level. The air gap is the vertical distance between the bottom of the hull and the still water level, which is the level of the water surface when there are no waves or other disturbances present. This measurement is important for ensuring a vessel has sufficient clearance to safely pass under bridges or other overhead obstructions. The other answer choices are incorrect because they include factors such as wave crests, tidal corrections, and storm surge, which are not part of the definition of air gap. Air gap specifically refers to the distance between the hull and the undisturbed water surface.

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