 German preparations along the Atlantic Wall were only partially finished; shortly before D-Day Rommel reported that construction was only 18 per cent complete in some areas as resources were diverted elsewhere.The deceptions undertaken in Operation Fortitude were successful, leaving the Germans obliged to defend a huge stretch of coastline.The Allies achieved and maintained air superiority, which meant that the Germans were unable to make observations of the preparations underway in Britain and were unable to interfere via bomber attacks.