" The only way I can safely avoid the risk of a midair with a glider is not to fly when the gliders are flying."
That's one way to avoid the gliders, but don't forget to include all the microlights, paragliders, paramotors and vintage aircraft that don't carry transponders (and which are of limited value anyway).
You also say "...without putting my passenger or myself at risk."
You're thousands of feet up in the air my friend - you have already put yourself and your passenger 'at risk'.
If you're really that concerned about it mate (a Grob 115 hit a glider awhile back - but glider/powered AC midairs really are quite rare) may I politely suggest you stick to sailing. Although even there you may wish to consider the words of John Donne.
"A ship in a harbour is safe. But that is not what ships are for."
Last edited by DaveUnwin; 22nd Aug 2015 at 15:24.
Reason: Missed a bit!