Which special feature is indicated by Special Marks?

Special Marks are used in the IALA Maritime Buoyage System to indicate areas or features that require particular attention but do not fall into the categories of navigational aids. They are typically yellow and may have specific symbols or markings that convey their unique meaning.

In this context, C, which refers to speed limits, is correct because Special Marks can be employed to delineate zones where operators need to adhere to certain navigation or operational protocols, which often include speed restrictions. This is crucial in safeguarding both the vessels navigating through these areas and the environment they are situated in.

Other options do not align with the function of Special Marks as clearly. For instance, Safe Landing Zones refer specifically to areas designated for land or dock activities and are usually marked differently, while High Traffic Areas and Salvage Operations refer to operational considerations but do not specifically correspond to the purpose of Special Marks. Recognizing the unique characteristics that Special Marks signify helps mariners navigate safely and responsibly in specific maritime zones.