What is a mourning buoy?

A mourning buoy is a type of buoy used in maritime contexts to signify the location of a submerged object, typically a sunken vessel or the site of a maritime tragedy. It serves as a visual marker for search and recovery operations, alerting other vessels to exercise caution in the area. Mourning buoys are often black or dark-colored and may be adorned with flags or other symbols to indicate the somber nature of the site.