KKF have fly-ins (with "enhanced" ceiling of 1500 feet) every couple of months. Next one is 24th July. See:
http://www.kentkiteflyers.org.uk/xoops/html/index.php
Capstone is a bit of a drive for me for casual flying, especially as the trees around the flying field render the wind a tad unpleasant from some directions; my usual site (Wye Downs at the Devil's Kneading Trough) is very overgrown at present, so I've taken to The Ridge in Ashford, or (when tide is out) to the beach somewhere between Hythe and Rye (depending on wind) if I have time to travel further.
And Blackheath is (for me) only about 10 minutes further than Capstone at the weekends; the wind there is much nicer.