Evan Ludeman wrote:

To Chris over in Europe... the US situation is rather different in
that a) the US is geographically huge and b) the US glider population
is very small. Glider clubs that launch eight gliders for a total of
perhaps 20 flights on a "busy" day account for a lot of US soaring.

While this is correct, think about what all glider pilots are searching all
the time: lift. As soon as you find a good thermal, the chance is that
another joins you very soon. Circling in thermals can get you very close to
other gliders, even if the airspace around you is empty. My near miss
happened at a small competition, we had a 250 km triangle. Even when we
crossed the starting line at different times we met each other again and
again, sometimes 5 or more gliders circling together at the same altitude.
When then the Flarm shriekes and flashes at another glider coming from
behind you can make a sharp turn out of the circle. Better loose some 20m
than your wing.

Another near miss happened at our airfield in the landing pattern, when an
inexperienced pilot came heading straight against another one who was on
correct course. They did not have Flarm and could avoid a crash in the last
second.

What does it help when there are only 10 gliders in a 1000km radius, but one
that flies directly into your cockpit? Collisions happen where there are
reasons to be at the same place, like traffic patterns and thermals.

Happy landings