I have read several books on the matter and have seen several more doco's on TV and the conclusion of the capacity of the Royal Navy is this, it is i known fact that capital sips such as Battleships, Battlecruiser, Heavy Cruisers and Aircraft Carriers were not to be deployed against the invasion fleet, they were to be deployed for the express usage in evacuation of the Government and Royal Family plus government and royal assets, such as the crown jewels, gold bullion, government document and the like.

That leaves invasion fleet interdiction by light cruisers, destroyers and submarines. Now i am assuming that the Royal Navy at the time could not have had as many as 300 destroyers in home waters at the time due in no small part as the RN was scattered throughout the world, and would take weeks to race back home.

And now onto the Air war, well it is a fact during Operaration Alder, Goring forbade follow-up attacks on airfields two days in a row, Goring ignored the importance of destroying the vital radar installations, and the Luftwaffe failed to attack centres of industry, such as aircraft production and repair facilities, also it failed to destroy the lines of communications such as roads and rail, and they needed only hed to achieve local air superiorority over South-Eastern Britain.

And onto the land war, Britain was in no shape what so ever in the land defense of home soil as the British Army had three fully armed divisions at the time, the rest were lacking in arms and equipment, let us not forget that Britain alone lost over 750,000 tonnes of war materiel in France and Norway that excludes the 70,000 vehicles it left behind, at full production that equates to at least 18 months of war materiel production lost.

But the only thing that would have made the job difficult was the fact that Churchill was fully prepared to use biological and chemical weapons, he indended to use both Mustard gas as previously mention and Anthrax, plus Britain did have one secret weapon the vast oil pipelines that jutted out into the channel, the intention was to flood the channel with oil and set it alight, immolating thousands of Germans troops.

But in conclusion Hitler hesitated and "he Who hesitates is lost". I belive German forces could have taken Britain and yes at a very high cost but taken it nonetheless, had thing been done right.