Re: Ignore the licence requirements
"They're invisible; daft as it sounds it can be difficult to see another paraglider in the wrong place"
After thousands of years of evolution on the savannas of Africa we have exhibit one, the human optical system. Something moving is immediately visible, say the lion running in against the grass. If there is no movement against the background we are apt to ignore what is in our field of view - no danger. An object that is going to collide with you is static against the background* (draw it on graph paper).
A para glider and drone, or two cars and a cross road, or a lion and lunch, are just experimental proof of the limitations of human eyesight.
* Assuming relatively constant velocity - a given in most circumstances.
Biting the hand that feeds IT
