Breakneck Bank event 19 June

[King Penguin]

... and by contrast I have had several instances where the presence of a competitor has specifically reduced the visibility of the control. e.g. at British Sprints I ran past one control because I was overtaking someone (obviously on the wrong side) on a different course who did not have that control and they blocked my line-of-sight to the control ! My fault I know for not being sufficiently in touch with the map, but even so .....
(Almost ?) every event must surely have some controls where the presence of another competitor helps someone. I know one of my 2 big misses at the British Classic/Long Champs would not have happened had there been someone else punching the control at the time.

No harm in aiming for perfection, but probably impossible to achieve if we have multiple courses and people starting on each at minute intervals. To remove the risk we would have to only start each competitor after the previous one had finished (or at least had no prospect of being caught) - clearly impossible. Even then, we would still have tracking up.

[LostAgain]

I'm sure everyone does their best to comply but it can't always be possible.
I'm a large man often wearing a bright shirt it has to be easier to look through trees and see me than see a control 1m above the ground in light undergrowth through the same trees if only because I'm usually wider than the trees (and unfortunately often the gap between them).

I think you are taking this to the extreme. We all know what the advice is aimed to achieve. Planners/controllers should act within the spirit of the advice. Orienteering is not a treasure hunt or bingo.

All of us have attended events where the navigation is deemed to be too easy, so the planner spices it up by hanging hte control low, or in some cases hiding it behind a tree within the feature, or wrapping around a rock at the bottom of a pit.

[IanD]

All of us have attended events where the navigation is deemed to be too easy, so the planner spices it up by hanging the control low, or in some cases hiding it behind a tree within the feature, or wrapping around a rock at the bottom of a pit.

Indeed we have, and by so doing, the planner has converted an indifferent event (terrain too easy) into a positively bad event (bingo controls).

[graeme]

what part of the V is the pit at? ... 3 or 4m

Show me a mapper who gets isolated pits that accurately, and I'll show you a liar.
I've often read about "fat M55" type tests, but its seldom adhered to. I generally work on the idea that if you run though the circle, you should be able to see something that's on the map. Maybe its the feature you want, maybe its another feature, but failing both of those, the flag. So in an area rich in details, the flag goes in the pit, in a vague area, its on the edge.

[70plus]

So are people saying that if you have a control site which is a pit or a depression(or ditch or gully or stream or any other negative feature) that you shouldn't actually put the control inside the feature?

I controlled at Bishops Wood (West Mids) twenty years ago. We used 64 controls, 27 of them at pits. They were good-sized pits, and visibility was also generally good (it was January). We trod a very fine line between making the controls visible from 10 metres or 100, but we tried to put the top of the kites just about at ground level. About the worst kind of control is at the bottom of a pit 2 metres square in a patch of mixed woodland.

On the other point, I always understood that a pit was at the point of a V, but a small depression was at the centre of the semicircle. Inconsistent?

[Red Adder]

ISOM is actually pretty consistent in its definition of the "V" and "U" symbol, of whatever hue. "Location is the centre of gravity [not mass] of the symbol". Some must be orientated north (eg pits) other may be rotated (eg caves)". Many of my earlier maps have pits of very inconsitent size and rotatation (eg "corrected version of Beaudesert Park JK 72 map !).

[Scott]

Location is the centre of gravity [not mass]

I was assuming that the symbol would normally be in a uniform gravitational field

[Adventure Racer]

My concern with putting 43 (reentrant bend) more in the open is that it would have been visible from over 50m away when descending the ridge towards it from the south.

Ah, well that was clearly my problem with it - I was expecting from the mapping that it would be visible over 50m away when descending the ridge from the South, having already been to 75 where it was visible from far enough away that I could correct my line in! Too frazzled by then to be sure enough of myself that I was in the right place - must have been within metres, but didn't look the right way.

Conversely I didn't have any problem at all with 61, given it was straightforward to navigate accurately to the ditch.

I still think 49 is one which is quite clear in the cold light of the planner's living room, but under race conditions I didn't spot the knoll either - if I had I still wasn't sure which pit was the middle one, which is what I'd argue was the problem with the control. On looking at the map coming out of the previous control I realised I needed to look at the control description which had to be something unique and distinct amongst the mass of pits... As it was I had the right line, so went straight to it, and it certainly didn't spoil my race at all.

[Gnitworp]

No harm in aiming for perfection, but probably impossible to achieve if we have multiple courses and people starting on each at minute intervals. To remove the risk we would have to only start each competitor after the previous one had finished (or at least had no prospect of being caught) - clearly impossible. Even then, we would still have tracking up.

The ultimate in fairness: a one year start interval with start times within a two week window equally disposed about a time exactly one year after the previous starter's start time to give the best possible chance of identical weather conditions

but late starters would suffer the extreme disadvantage of extreme old age

and parts of the forest may have been felled or become greatly more/less runnable

Back to the drawingboard, gnitworp

[Adventure Racer]

but late starters would suffer the extreme disadvantage of extreme old age

Added incentive to enter early - not quite sure how it works for us folks who like to enter on the day.

I suspect the later starters might also get a bit fed up with being kept in quarantine (to ensure they didn't see the Nopesport discussion on the event).

[70plus]

Show me a mapper who gets isolated pits that accurately, and I'll show you a liar.

Graeme, you forgot to add 'in forest'. My club has limited access to an open Welsh hilltop area used for C18-19 lead mining, littered with pits of all sizes. I mapped it 30 years ago from a decent photoplot, and we still use an OCAD version of the same map. Contours and pits are about the only things whose position can be relied on - many paths and much vegetation are completely different.

[pete.owens]

... but presumably, all those pits are mapped exactly 7m north of their true location!

[andypat]

I once had an entire map mapped 100m west of where it should have been but nobody noticed....

[Muddy Boots]

I once had an entire map mapped 100m west of where it should have been but nobody noticed....

If it was the entire map and provided the north point was correctly set no one would notice. As a mapper and controller from time to time I have come across maps where the north point has been incorrectly adjusted! If this is significant and if not corrected it definately could be noticed.

[graeme]

I once had an entire map mapped 100m west of where it should have been but nobody noticed....

They had one of those at the JK once. Which was fine until they combined it with the next bit of forest which was mapped in the right place...