On Topographic Bathymetric maps, how is a Sunken rock depicted?

• A. A shaded area marked by a plus sign
• B. A blue dot
• C. A cross hatch
• D. A dashed circle

Answer: (A)

On these maps, underwater hazards are shown with symbols that combine shape and shading to convey both what the feature is and where it lies. A sunken rock is depicted as a shaded patch on the seabed with a plus sign marking the exact location. The shading signals that the feature is a rocky area below the surface, while the plus sign draws attention to its position, which is essential for navigation. Other symbols would not communicate the same idea: a blue dot is more like a discrete point feature, not an area of rock; cross hatch points to something different and isn’t the standard cue for a submerged rock; a dashed circle suggests an area of uncertainty rather than a known sunken hazard.