ORIGINAL: KoenigMKII
Colin, thank you for the correction about the Forward Luftwaffe bases in the Pas de calais.
Found the moon table for 1940. May need to correct times for UK as these may be US times, unless universal time= Zulu time=GMT??
1940 Phases of the Moon
Universal Time
New Moon-----First Quarter-------Full Moon------Last Quarter
---------d h m -----------d h m------------d h m------------d h m
---Jul --5 11:28---Jul 12 06:35-----Jul 19 9:55----Jul 27 11:29
---Aug--3 20:09--Aug 10 12:00---Aug 17 23:02---Aug 26 03:33
---Sep--2 04:15--Sept 8 19:32----Sep 16 14:41---Sep 24 17:47
---Oct--1 12:41---Oct 8 06:18----Oct 16 08:15---Oct 24 06:04
As for air superiority, I say it can't be achieved unless and untilSeelowe begins,
It could be argued that the Luftwaffe
did obtain air superiority -- briefly, and of only the most limited kind -- over Southeast England in the first week of September.
In any case, wether they historically did or not or could or not, in my view, the Germans
have to gain air superiority
prior to Seelowe. They need to drive the British Navy far enough away so that it cannot interfere with the crossing. That boils down to making it prohibitively expensive for the British to continue basing destroyers and light cruisers at Portsmouth, Sheerness, and Harwich. This in turn pretty much demands substantially greater success in the Battle of Britain than was historically achieved.
in fact if the moonlight were matched by fair skys [big if, but if forcast was favorable...] telegraphing the invasion 24hrs before might induce British RAF attacks because of political pressure.
Anyway, as soon as the Kriegsmarine begins loading troops and towing barges all hell will brake loose.
The RAF was bombing the invasion ports already. I'm not sure what they would have started doing that they weren't already engaged in.
I am playing devils advocate here, but the germans planned to beach barges at high tide and let the falling tide make it possible to unload the men and equipment in shallow water. Those barges need flat sea to make it across - so clear skies with low wind - thats asking for a hell of a lot.
I think the crossing has to be attempted in daylight, but the barges are slow. 6-8 hours to cross, midday is 8 hours from dawn in the summer.
What with loading up, clearing the ports, marshalling the tow formations, etc, it was going to be more like a 36 hour operation.
The real Hitler would never have risked it, but it is curious to take his place as CIC and give the order. Is there a high tide on the south coast just before miday on any of the day following August 17, for example, ?
I forget the exact dates, but the Germans wanted to land around dawn, about two hours after high tide (the barges have to be refloated -- you don't want to land at high tide). That pretty much put them into two five day windows: August 20-25 or something and September 17-22 or something.
Did the Germans even have enough air-sowable sea mines to form even one side of the protective minefields required to allow the follow up waves and supplies? Not enough surely, so it would have to be a patchy barrier.
No minefield forms an absolute barrier. They merely impose risk and delay. That is all they were expected to do.
I think all ships up to battleships are vulnerable to the stuka HE bombs. The only part of a battleship that would be vulnerable is the Parallax gun director - that is a very lucky hit indeed though, and it is essential to the accuracy of the main guns only - secondary/tertiary could use adhoc meens to lay the guns. The only hope to stop the British battlewagons are torpedos (not many U-boats this early in the war.) and mines.
The battleships only have to be stopped if they come, and in fact, the British were unwilling to risk their battleships in the Channel -- at least in their initial response. They'd had a nasty experience off the Norwegian coast when HMS Barham was hit by a bomb from an HE 111. While the damage was minor, it made them averse to employing battleships in areas where the enemy enjoyed air superiority.
Later on of course, if it began to look like the Germans were going to hold their beach head, the British might well have sent the battleships in. However, at that point their intervention wouldn't have been decisive. They could briefly interrupt the flow of supplies and reinforcements, but they couldn't just anchor in the Channel, and once they've left, the Germans can resume crossing.