Off the coast of France an international team is exploring a hidden battlefield, looking for the secrets of how the greatest naval mission in history unfolded. Buried here is a treasure trove of ships, tanks and potentially unexploded mines, these are the wrecks of D-Day. June 6th 1944, for years Hitler had devastated Europe killing millions and now is the time for the allies to make their move but the odds were against them. Three years in the making this was the most epic struggle of the 2oth century.