What does a Cardinal Mark signify in the IALA Maritime Buoyage System?

In the IALA Maritime Buoyage System, a Cardinal Mark signifies that there is a danger that must be navigated around. These marks indicate the direction of safest navigable waters relative to the danger they represent. Cardinal Marks are categorized into four compass directions – North, South, East, and West – each represented by specific colors and shapes.

For instance, a North Cardinal Mark indicates that the safe water lies to the north of the mark, while a South Cardinal Mark points to the safety lying to the south. The distinctive black and yellow colors of these marks enhance visibility and convey information about the water surrounding hazards. Knowing how to interpret these marks is critical for mariners to navigate safely and efficiently, avoiding potential dangers.

In contrast, other choices either suggest indications of safety or specific navigational features, which do not align with the function of Cardinal Marks in the buoyage system.