[Jon]

The Battle was won at the end of October, this was the last realistic time for an Invasion to be launched when the weather would not have been a major problem for the German army at sea in low draft barges. As we all know the air war carried on with RAF and Luftwaffe losses every day over Britain and the sea.
I just think Britain then thought of the air battle as a part of all what had happened before, France dunkirk etc...just an extension to this.
The leaders on both sides realised that if it did not happen in 1940 then an invasion was off as, by the summer of 1941 Britain would be and was ready to decimate any attempt at sea.