Which buoy shape is commonly associated with a North Cardinal Mark?

The North Cardinal Mark is characterized by a specific buoy shape that aids mariners in identifying navigational routes safely. The pillar or spar shape is commonly associated with this type of mark. This design features a tall, vertical structure, which makes it highly visible from a distance. It typically has the colors black and yellow, with black being predominant, and it displays two upward-pointing black triangles.

The distinctive shape and colors help indicate that the safe water lies to the north of the buoy. By understanding this association, navigators can make crucial decisions regarding their course, ensuring safe passage and avoiding hazards. The uniqueness of the pillar or spar shape, coupled with its color scheme, reinforces its recognition as a North Cardinal Mark within the IALA Maritime Buoyage System.