Discussion: how to map a fissure (crack) on the ground

not a pit.
more like a hole on the ground bounded by two facing rock facades

215 Trench
Rocky or artificial trench. Minimum depth should be 1 m.

I see...

What are the dimensions, specifically, how long is it?

looks to me it is about 6-8 m long

the terrain has plenty of fissures that start from flat ground and develop in quasi-canyons, as seen here

Exagerating to 4 times its length with the minimum trench symbol size? I would use the pit symbol.

2017 symbol set has a symbol 201-006 Impassable cliff, pit which perhaps could apply

The video definitely looks like a trench and should be mapped as such. Notches into cliff walls maybe as caves.

Fill it with dirt and make your mapping life that much easier.

It was difficult to judge the scale of the photo, and I would originally have said a rocky pit. However, the video makes the scale clear. According to ISOM 2017 it's an impassable trench, which must be mapped as two impassable cliffs with a 0.4mm gap. This would mean a massive displacement of surrounding features, so what you have may not be usable.

The Czech mappers of the Bohemia 5 Days, and Rob Vincent (NSW Australia) who have mapped similar rock passages might be able to give you advice.

Now I've seen the video, it is clear that they are impassable crags, that end as a small fissure. It is important to show that they cannot be crossed, but one can pass down the gap between them. The sandstone areas of Czechia have many features like this.

Here are some examples from Euromeeting 2010: http://www.tur.cz/pekneprazdniny/2010/archiv/eurom...

Perhaps the mapping style of Urbasa in northern Spain could help: http://www.nordesteorientacion.es/wp-content/uploa...

For the areas that you can go through or pass under, the mapper marked them in pink. There's an example south of leg 9-10.

Purple crosshatching.

How about mapping at 1:10k then? Oh sorry. I forgot. Thats not allowed.

How about mapping at 1:10k then? Oh sorry. I forgot. Thats not allowed.

or 4000 like Spanish map

According to current rules, ISOM 15K or ISSOM 4K are the only legal scales, with the only option to make pure enlargements.

It is however quite obvious that those sandstone terrains, as well as many cliffy coastal areas in Scandinavia and around the world would in fact be much better served by allowing ISOM 15K symbol sizes on an enlarged map, i.e. something like 1:10K or 1:12K. You will of course still enlarge this by 30 to 100% for older classes.

Personally I intend to encourage tests here in Norway, printing maps both ways and allowing elite and regular competitors to judge what they find best.

The IOF way seems to be one map specification, and one scale, per discipline, more or less. Maybe we needa new discipline called Limestone Orienteering, and ISLOM.

The same scale for middle and long. Middle to 10 would solve quite a few issues.

@TheInvisibleLog: Middle & Long do have the exact same ISOM standard, except that Middle is usually enlarged from 15K to 10K: What we need to be able to map more detailed terrain is 15K symbols on a 10K map (or something similar).

Ugh...