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Uncrossable marsh 309

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This page contains content from ISOM2000   This page contains content from Ashby Mapping  Ski-O symbol  Mountain Bike-O symbol    revision 05/00


309 Uncrossable marsh

A marsh which is uncrossable or dangerous for the runner. A black line surrounds the symbol.

Colour: blue, black.

Bank line width 0.18mm, blue marsh line 0.25mm

Line spacing 0.25mm (0.5mm line to line)

This symbol is oriented to north.

ISOM 1990 Definition

As ISOM 2000 but bank line width was 0.175mm, and the combinations have been changed

OCAD Methods

Defined as area symbol 309.0, and can be drawn with any drawing tool.

Care is needed at joins, overlap only where it is safe (usually if it is the same colour and always if it is the same symbol). If you need to share a common boundary with another symbol, draw along the edge with the control key to follow it exactly.

Underlying area colours will show through the symbol in the spaces between the blue lines, as no underlying colour is allowed, the symbol must be edge matched.

Drawing Considerations

If there is any possibility of danger to runners, then this symbol must be used.

This is a symbol that must have a distinct edge even if there is no mappable boundary on the ground. If the edge is indistinct, surround this symbol with the marsh or indistinct marsh symbols. Strict edge matching will be needed or the blue lines will clash.

Permissible Combination of Screens

The ISOM lays down the permissible combination of screens.

Uncrossable marsh may now combine with 401, 402, 403 & 404, cut all other screens to the edge of this symbol.

If this symbol is used in a yellow area, especially a full yellow area (open land), then it will tend to green out, as both the blue and the yellow will print.

If you use the colour table hint to knockout the yellow, as described in the full blue topics, then there could be a problem with white edges to the symbol with any print misregistration.

There are more details in the Main Help File or in the Colour Help file.

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International Specification for Orienteering Maps produced by the International Orienteering Federation
OCAD produced by Hans Steinegger Software. 1988-1999 Hans Steinegger. OCAD is a registered trademark of Hans Steinegger
This document has been written and coded by Peter Hornsby of Ashby Mapping
Apologies for any mistakes and errors; please inform details of any problems, thanks.
Produced for the Ashby Mapping internet site on 20 November 1997 and 1 December 1999  1997-2000 Ashby Mapping
Revised 28 December 1999, 23 March 2000