What detail can be left off the map?

[Freefall]

What sort of event are we talking about?

Northern Championships. I am inclined to leave the tower off - it is not at the top of the hill but in a dip beyond. It is fairly close to the bearing competitors will run on to their control on many of the longer courses.

[Red Adder]

If its the Northern Championship I would hope that a map adviser has been appointed. In that role I would strongly advise (probably insist) that the mast was on the map. Starting to omit features to tickle up a map a bit and make it more difficult is a bad route to start off down.

[Gross]

Controller & planner should offer an opinion as well! It's not the job of the mapper to make controlling / planning decisions.

[AndyC]

Freefall is the planner

[Gross]

Well if he's planner he shouldn't be mapper for a big competition.... but that's another discussion

[greywolf]

Can't see any justification for leaving such a significant feature off the map in this case (it's not obscuring anything else) - as Graeme says, the map is there to help not hinder competitors. It's the planner's job to make the courses as technical as the terrain allows, not to arbitrarily fiddle the map to make it confusing for a random subset of competitors.

[Freefall]

Opinion does seem to be split on leaving features like this in or out. I am a very experienced planner and controller as it happens (as well as a very experienced competitor) and I do know that on previous occasions where I have orienteered on areas with significant features such as a radio mast they rather take away from the navigational experience. I still haven't seen rules or guidelines in leaving features on or off - only some rather poorly thought out reasons in the opinion of some individuals as to why the feature should be left in.

Well if he's planner he shouldn't be mapper for a big competition

Maybe you have already orienteered in big competitions I have planned in the past. Were you happy?

[Scott]

I still haven't seen rules or guidelines in leaving features on or off - only some rather poorly thought out reasons in the opinion of some individuals as to why the feature should be left in.

At least to me, ISOM (surely the first place to look?) seems pretty clear and unambiguous on this:

The map must contain the features which are obvious on the ground to a competitor at speed. It must show every feature which could influence map reading or route choice [...] The map must show the features which are obvious on the ground and which are of value from the point of view of map reading.

[NeilC]

I still haven't seen rules or guidelines in leaving features on or off - only some rather poorly thought out reasons in the opinion of some individuals as to why the feature should be left in.

Wow. To add to Scott's quote from ISOM

"The general rule should be that competitors shall not perceive any inaccuracy in the map"

In bold in ISOM to emphasize it's importance. Hardly poorly thought out.

[Freefall]

Interesting - ISOM was where I first looked and I couldn't actually find a reference to leaving power lines out. Maybe I didn't look in the right section. That's how the argument went on to suggest maybe met masts could be omitted, though of course they don't run along other features such as rides. I guess that though I think it will lessen the navigational experience (at speed or not) the mast must stay.

[Scott]

Interesting - ISOM was where I first looked and I couldn't actually find a reference to leaving power lines out. Maybe I didn't look in the right section.

Appendix H to the BOF Rules ("Mapping"):

Any map used for a competition at National (Level 1) and Regional (Level 2) events must be drawn according to ‘International Specification for Orienteering Maps 2000’ (ISOM 2000), or for sprint maps ISSOM2007, subject to any specific British Orienteering amendments described in this Appendix. It is recommended that maps for Local (Level 3) events should follow these specifications if appropriate. The map should be up to date and reflect the current state of the terrain at the time of the competition.

Not been updated for the four-level era yet, but I would interpret it as allowing you to deviate from ISOM by omitting power lines "if appropriate" at a Level 3 (Level D?) event, but not at Levels 1 and 2 (A, B and ?C).

[Urban]

It's a no brainer of course the mast stays on, ISOM and BO Rules make this clear. Where will it end? leaving off features to make the navigation trickier is wrong.

[DeerTick]

It's a no brainer of course the mast stays on, ISOM and BO Rules make this clear. Where will it end? leaving off features to make the navigation trickier is wrong.

Absolutely agree.

But we could have a 4-level map grading :

Level 1 : everything shown

Level 2 : no power lines, masts, roads, buildings

Level 3 : no paths, fences, walls

Level 4 : no linear features whatsoever

And, yes, I've considered Level 5 (point features only) and Level 6 (completely blank map - very cheap).

So now we'd have a new challenge for the ranking algorithm - is a 60 minute time at Level A, Level 1 worth more than 60 minutes at Level B, Level 3;etc.



Happy New Year.

AP

[Freefall]

It is clear - the mast stays on. From what I read the power lines must also stay (the area has some). I am pretty sure that I have run at major events where these were missing - does that mean wrong decisions were previously made or did the rules change?

The map grading isn't so bad an idea - I remember running at Amphill on a map with contours only.

[ryeland of doom]

Power lines are interesting as there is a hierarchy. While the big towers and high voltage lines running through huge rides are pretty hard to omit, there are often domestic lines on poles. Sometimes these are mapped, other times not. I have always omitted them.
In forests they always run beside roads or along rides, well away from trees, so at least you get a vegetation boundary - missing the actual power line saves clutter on a busy bit of map.

I have also noticed that it is common to map towers, but leave the lines off for clarity.