What does a cardinal mark buoy with a yellow top and bottom and a black middle signify?

A cardinal mark buoy with a yellow top and bottom and a black middle signifies that it is marking the safe passage to the west of a hazard. In the IALA buoyage system, cardinal marks are used to indicate the position of underwater hazards and indicate the safest navigable water based on the cardinal direction.

For this specific buoy, the color scheme indicates its direction: while yellow is typically associated with the cardinal system, the black marking affixed in the middle is distinctive to this representation, differentiating it from others. The combination of colors serves to guide mariners accurately, ensuring that they understand which direction to take to avoid hazards in the water effectively. For example, if a mariner is navigating towards the west, passing on the west side of the hazard is recommended when observing this marking.

The understanding of cardinal marks is crucial for safe navigation, as they are emblematic of specific locations in relation to underwater dangers.