INT 1 · K 13

Dangerous underwater rock, depth unknown

DangersCore

A cross inside a dotted danger surround marks an underwater rock of unknown depth.

What it means
A cross within a dotted danger surround marks an underwater rock whose least depth is unknown and which may endanger surface navigation.
Why it matters
The dotted surround emphasizes a point hazard; it is not a surveyed exclusion radius. Decide clearance from scale, depths, tide, sea state, and position accuracy.
IHO INT 1 — K 13