Hello Simon,
Administrative problems seems to bug us all over the world, I have been restauring and reselling a few flats, and one of the biggest constraint was often the French administration.
Concerning the movie the main diver is Innes McCartney.
I copied a few facts about him, but I am certain that the people that live in England can somehow contact him.
Innes McCartney is an historian and nautical archaeologist, specialising in 20th century naval vessels. He lectures widely on a number of associated subjects. A passion for shipwrecks has led to some famous discoveries, including the submarine M1 and the battlecruiser HMS Indefatigable. His previous book, Lost Patrols detailed his uncovering the 121 submarines sunk in the English Channel. He lives and works in Penzance, Cornwall.
Dive magasine gives anothe adress:
Born 24 March 1964, London
Lives Cookham, Berkshire
He is also, the editor of Periscope magazine:
http://www.periscopepublishing.com/I hope that these info can help you a bit,
Cordially,