edit: updated map and download link included
I have been working on a large-scale map of the English Channel for my own use but you are welcome to use it if you want. It's a 10752x9126 pixel PNG, weighs in at just over 90MB and was generated using some of the Cliffs of Dover game assets. Airfields and major urban areas are shown though the map is still a work-in-progress and additional airfields, towns and other landmarks will be added in future.
There are a handful of known issues e.g. in some cases text label placement and colours need to be tweaked for readability.
Download link:
http://www.megaupload.com/?d=N5TH44FT [edit: updated link to the final version of the map]