A marsh which is uncrossable or dangerous for the competitor. The black outline emphasises that the feature is uncrossable. The black outline is omitted for boundaries between uncrossable marsh and symbol Uncrossable body of water (301). The symbol may be combined with a rough open land symbol (403, 404) to show openness.
The symbol is orientated to north.
Minimum width: 2 lines or 0.8 mm (inside).
Smaller areas must either be left out, exaggerated or shown using symbol
Uncrossable body of water (301).
Colour: black (outline), blue.
The definition of this map symbol was updated on 15.02.2022: Change of minimum size.