A unique standard ENC symbol that is used to mark the location of a potential danger (rock, wreck, obstruction) whose sounding if known is shallower than the effective safety contour and that lies outside of the safety contour. The symbol will also be applied to such dangers whose sounding is not known.
It is a magenta circle, with a prominent transparent bold X in the middle.
The symbol is used relative to the actual safety contour in effect, which may not be the numerical value the user has entered, because when the chosen value is not a native contour in the chart, it will assign the next deeper contour as the safety contour, which will be indicated by a bolder contour than the others on the chart display.
