Where have I heard this before?

This whole thing seems to be a repeat of a book published in the late 1960’s by a former naval officer. Unfortunately i can’t remember the name of the book, since like most of my life, its in storage. The idea is perfectly reasonable in itself, since its pretty clear that the Germans were not really prepared materially to able to launch an invasion in the way the Allies did in 1944. The tank transports would have capsized in anything rougher than a millpound and there were not enough destroyers, etc. This was fairly clear to much of the german military itself, and seemingly a lot of them were going through the motions.

But i think the thread has hit on the flaw in the argument. British ships might have been devastating to any invasion fleet, but they had to able to reach the Channel, which meant that they had operate with air cover (the convoys attacked in the early part of the battle were stopped because of the cost in ships), and if they were in ports such as Portsmouth, Plymouth, Ramsgate and the like, they would have been vunerable to bombers while in port, and would have had problems while at sea, at least if they wanted to operate in daylight.
I remember one author pointing out that no bomber was able to carry a bomb large enough in 1940 to go through the deck armour of a capital ship, which meant of course that he could simply ignore the Luftwaffe. I’m not sure it was even true, and frankly it would be an unpleasant experience for a destroyer to be under attack from a couple of Stukas. Certainly the idea of the Grand Fleet steaming down from Scapa unmolested by the Luftwaffe (even just dropping mines) is difficult to imagine. The RAF gave fighter cover to the fleet, both in harbour and at sea, helped prevent the destruction of the industrial base upon which the war effort depended, and meant that air superiority was simply not available to an invasion fleet. Bomber Command also helped destroy whatever barges they did have available.
The RAF kept us in the war, and meant that the isolationists in the Us could not simply write us off, which meant that lend lease could become a reality. The navy scared the Germans, but the RAF meant that they never had to face them in the first place, at least not crossing the Channel.
Frankly, there is useful revisionism and there is trying to make a name for yourself…