All I can say is that the German documentary was fairly forthright in stating that the invasion was a sham. It is so long ago now that I can't recall the sources. It certainly hit my conception of the BoB for six, although I am still a little sceptical.
Didn't Napoleon aim for a "window of superiority" in the Channel to get his troops across and almost pulled it off, Nelson dutifully following the excursions of the French fleet, but luckily informing the Admirality which in turn fortuiously picked up the French fleet on its way to the Spanish coastline. Was such an attempted deception something that Hitler could have pondered or were communications by that time so far advanced that a bluff of this nature would not have worked?