Denis wrote:

I don't know which competitions you are speaking about, nor their
particular rules. I am refeering to SC3 annex A, where the distance is
calculated by the turn point itself, center of the beer can.

Do you have a reference for this? How big is the beer can?

Look at the agenda of 2004 IGC meeting on www.fai.org/gliding site (I
don't know if the proposal has been approved by the plenary, but it is
likely because it was a year 2 proposal) .

The beer can has a 500 m radius like in Annex A, and 1 km is subtracted
from the distance at each turnpoint when beer can is used.

Hmmmm...I wonder if I declare a course which is 300.1 KM, and
then go fly it by turning each point just outside the point by
a few hundred meters, if this means I will be 3 KM short...

I suppose for any task it makes sense to tack on a few extra km,
and be extra sure to hit the OZ (maybe two tight turns around the point)
to make absolutely sure...

Still dunno why a beer can was ever introduced for anything...
See old threads for arguments on this...
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Mark Boyd
Avenal, California, USA