Under the IALA-A and B Buoyage Systems, a buoy with alternating red and white vertical stripes indicates __________.

Correct Answer: Option D — that there is navigable water all around

Safe Water Marks, defined by IALA, feature red and white vertical stripes. These marks indicate that there is navigable water all around the buoy. They are often used to mark the center of a channel or a landfall, and they may be passed on either side by the mariner.