Could "Sea Lion" have succeeded?

[Rodion Romanovich]

A few more thoughts:

- If Sealion would have been attempted, wouldn't the British Mediterranean fleet have been pulled back to assist if necessary? There must at least have been a feeling among German High Command that it could have happened. But on the other hand, wasn't effective radar controlled anti-air attached to ships much later, some time during 1942 or even later? Which meant British ships probably weren't that good at anti-aircraft fighting.
- When exactly did the air war over Britian reach a state of German air superiority? Wasn't that in the middle of August that the Luftwaffe offensives started to get some superiority over Britain. August was too late for an invasion according to normal doctrine. Which meant the invasion probably couldn't happen that same year, so early 1941 would have been the first possibility, but by then the air war over Britian had already been lost by Luftwaffe. By November or so the Blitz was carried out. Already in December 1940, RAF was able to carry out daylight bombings over several targets on the mainland. The German planes moved to the Mediterranean to assist first the Italian fleet and Rommel, then also the invasion of Greece and Yugoslavia can't have had a too important role in this defeat in the air war over Britain - having kept them in France wouldn't have changed much.
- Another factor speaking against an invasion attempt in late 1940 was that there was no way of telling whether France had calmed down or could turn into open war again at that time. So April or May 1941 was probably the first good chance for an invasion.
- However in April 1941 British air strength was enough to carry out a raid against the cruisers Gneisenau and Scharnhorst, which were damaged, later making them unable to join Bismarck's cruise. In May, Bismarck was sunk, British aircrafts having some role in the engagement, and British ships no longer being so scared by the Luftwaffe they didn't dare moving ships almost freely through the channel. With 3 of the most important Kriegsmarine ships out of action the invasion was then out of the question.
- The German occupation of the channel islands suggest that Germany would probably have been able to insert forces in Britain, but the supplying capabilities would then have been the crucial problem.
- The moving of half of Britain's tank reserve to the Mediterranean theatre showed that British command considered Sealion impossible in 1941 (I think it was then that they moved the tanks there, but not sure)
- The two chances of a successful Sealion would then probably be: a rush in August 1940, or withdrawing from the air war in Britain during late 1940, then beginning air offensives again in early 1941, and in either case refrain from bombing cities. RAF would probably have plenty of time to build up during that time, as well as buying planes from USA. So as so many other times, naval duels would have decided the war. Being able to effectively cut off supplies to Britain with subs and other methods would have been difficult.