Kirk Stant wrote:
...
Most of the time, the Mk 1 Mod 0 Eyeball works fine - IF you can look
in the direction of the threat. Fine during thermalling (plus you are
easy to see, assuming the other guy is also looking out...). But
during long glides between thermals, you CANNOT SEE the threat running
you down from behind.
...

Yes, I remember a huge glider (well, only 15 m, but so close it seemed
really huge) coming just above my head during such a glide, because
it left the same slope as myself just a few seconds after me, just a
few meters higher and flew just a little faster than me. None of us
could see the other glider just up to this moment.

But there is a simple device that could help in this case, which is
fitted in most motor gliders with a retracting prop: a small rear
facing mirror. I wonder why we don't have such a mirror on every glider.