As mentioned in many of the papers, and experiencing high levels of use currently...
http://www.britainfromabove.org.uk
I did try searching for Dover, but all there is at this time is...
"Our system is currently experiencing an extraordinary level of traffic. Please bear with us."
There is a taste here though...
http://www.guardian.co.uk/artanddesign/gallery/2012/jun/25/rare-aerial-photographs-britain-in-picturesIgnorance is bliss, bliss is happiness, I am happy...to draw your attention to the possible connectivity in the foregoing.
