Agreed, providing the logistical tail works and the follow up forces arrive.And once the Panzers are in, Britain goes down.
The British Home Fleet at the start of July 1940 had the following available for home defence:-
3 Battleships
2 Battlecruisers
11 Cruisers
80 Destroyers
plus a further 10 Cruisers and 52 Destroyers were on Convoy duties.
The immeadiate RN response to any German invasion would be by some 5 Cruisers and 42 Destroyers based in Plymouth, Portsmouth and Harwich/Sheerness. Plus the various Patrol craft that numbered in the many hundreds. Germany could sail 8 Destroyers and some SBoots to defend there fleet at sea.