I too would think that skydiving would be very unsafe for a ferret.  I
would worry about their intake of air on the way down, the change in
pressure on their little bodies, their already fast heartbeat, and any
unexpected impact upon landing.
 
If you are seriously considering this, I would ask your vet if it is safe.
Ferrets don't have great eyesight, and they don't always realize how risky
some of their jumps are.  My fuzzies dance all over my bed right up to the
edge, then they look astonished as they fall to the floor.  Good luck with
your decision!
 
Hope you have fun on your jumps!!
 
Risa
[Posted in FML issue 3676]