Thanks for the warning Zeemax, I've just spoken to them and you're right .. they say skydiving isn't covered.
Personally I think they'd have a hard time defending that in court, the policy said parachuting was covered and as you pointed out there was a picture of a skydiver on the website.
Skydiving's a branch of parachuting isn't it ? Well I've cancelled now, guess I'll look at AXA.