Sounds as if you were treated to an exciting visit RW, never knowingly seen a Hobby flying, only know what one looks like from viewing New Forest live cam of Hobby's nest & that was a thrill (but sadly nonproductive this year!)
2013 photos & vids here
eff37 on Flickr
hi Wendy -as i said it was my first ever sighting and the sort of thing that makes birding worth while -hope you see one soon---I had another good afternoon at St Aidens -lovely big female Marsh harrier.