O boy, here we go! Our gliding club requires annual refresher flights before going solo every spring. Including stalls, spins and spiral dives.
Not that glider pilots, Rusty Sparrow, are specially talented and fearless.
Rauxaman posted that the spin was demonstrated from 700' on the downwind leg. Not any more, it isn't approved by the BGA. They were just too cheap to pay for an aerotow, or not able to climb in a thermal to an appropriate height before spinning. l,800 is my personal limit before spinning a K13, that dear old reliable and trusted trainer.
When I was on the instructor course at Booker, they used to use the 700' spin to demonstrate the phenomenon called GROUND RUSH! Not nice. (You use up 300' in the recovery).
Some types of gliders can be trusted. Others have a very nasty record of killing people in spin training or biting you when least expected, eg turning on to base. A K21 is amost impossible to spin, without lead weights on the tail. A K13 will not spin if the guy in the front needs to go on a diet.
A Puchaz does exactly what it says on the tin. Watch out!
The difference between a spin and a spiral dive is well demonstrated in the K13. If the elevator does not work in the normal sense (stick back, nose DOESN'T go up) you are stalled. If the nose is pointing down at the scenery and it is turning around, you are spinning.
Power pilots, if you would like this experience, look at the British Gliding Association website, and sign up at your local club for a course.
Not nearly so scary as spinning a Chipmonk or a Aerobatic l52. And we practice it a LOT.