what 861 warships?
They had couple capital ships plus dozen cruisers and 76 DD/FF. Several times this number was available but strung out around the world. It would take week or two to return them to the UK.
Most counter invasion forces were 750 trawlers armed with either 12lb gun from WW-I plus AAMG or the ASW versions with ASDIC , DC racks & AAMG. At most 1/2 could be available to counter any invasion. There primary mission was coastal convoy escort work and in what ever clashes they were involved with they were a pain in the ass to sink . Admiralty wanted to use these trawler "warships"in Atlantic convoys , since the average convoy had only one escort...no wonder the Nazi had a field day with the convoys.
Historically most attacks on auxiliary vessels resulted in maybe one vessel sunk per attacking warship sortie.
The 861 vessels includes approximately 200 FFL ships, for which I don't have a lot of data. there were approximately 693 RN ships srawn mostly from dover,Harwich and nore commands, including the following
CLs -1
CLAs 2
DDs 59
Sloops and corvettes; 19
Large PCs; 9
Gunboats 12
MSWs; 56
Large TBs and ocean going ASW craft (eg the Hunts, Kingfishers) 33
Armed yachts 151
Small boarding vessels; 94
Ocean boarding vessels; 9
Minelayers; 7
Special service vessels: 16
Armed Tugs: 54
MTBs and MGBs: 46
Other armed Patrol craft; C 50
By the time the sealion operations loomed into view these forces had been substantially reinforced, to over 1000 warships, mostly coastal forces, spread from Harwich to brighton with about as many within another 8 hours sailing time.
Your right that these forces were strung out ant it would take time for a 'big wing" response to be mounted if the invasion fleet had gotten under way. The admiralty thought about a day at most, DKM estimated twice that. The defenders still had 9 days of attacks in which to decimate the invaders.
Most counter invasion forces were 750 trawlers armed with either 12lb gun from WW-I plus AAMG or the ASW versions with ASDIC , DC racks & AAMG. At most 1/2 could be available to counter any invasion. There primary mission was coastal convoy escort work and in what ever clashes they were involved with they were a pain in the ass to sink . Admiralty wanted to use these trawler "warships"in Atlantic convoys , since the average convoy had only one escort...no wonder the Nazi had a field day with the convoys.
in the event of an invasion alert the admiralty orders to these ships were basically to drop everything and proceed immediately to their assembly points, and from there to proceed to positions to repel the invaders. there would have been no holding back on this. these coastal forces were there principally in 1940 for the sole purpose of defeating the invasion. from the end of july all east coast convoy traffic had been halted or diverted. there weren't any "convoy distractions" except for 1 or two here and there undertaken for propaganda purposes mostly. Most of the larger ships were armed with 4.7 and 4in, also quad 2pdrs, the middle sized ships were armed with 4in guns and 0.5in HMGs, the smaller conversions had a rather disheartening array of old weapons, the same as was the case in the DKM conversions that made up the majority of their forces.
You cant compare what would have happed here with anything during the war. It was a quite unique situation. I agree that initially the germans and the allies might find themselves in a standaoff....until the Germans run out of ammunition, then what???? They have no choice but to withdraw to replenish. once this nibbling process is over, those transports are fully exposed and vulnerable, with no real defences. on the few occasions that i can think of where anything like this happened, usually in remote corners of the eastern front, massacres did take place. We have nothing like that in the western hemishere, but it would extremely wrong to claim that it would never happen. It never happened, because nobody not even hitler were dumb enough to risk a fleet so totally vulnerable to attacks like that.
Some of the warships mentioned were capable of use in the western approaches, but were not attached to that command and had not since the beginning of the war. the majority of the coast forces were just that....coastal forced, not capable of ocean service. The Uboats were having a field day and continued to do so until the following March. but these coastal forces that you are so scornful of had in fact succeded in driving the uboats away from the UK coastal waters and out to the open sea. Had france not fallen, there would have been a reprive to a degree from the uboats, but the new uboat bases along the French Atlantic coast had given the uboats an extension of range that very nearly brought Britain to her knees. moreso than some half baked crackpot invasion. .