Sea Lion exposed the gap between invasion plans and naval reality

German planners sought roughly 1,800 river barges, 500 tugs, 150 steamships, and 1,200 motor boats to carry the Ninth and Sixteenth Armies across the Channel, with the Eighteenth Army following later. Barges and tugs could not secure the crossing against the Royal Navy. Worthing's sand and shingle, raised bank, dip behind the beach, and nearby urban area complicated a landing, while tides and shallow water restricted naval fire support. Lütjens proposed sinking pre-dreadnoughts in the Channel to obstruct the Royal Navy's approach to the crossing fleet. The proposed landings also pointed toward a defensive sector prepared under Bernard Montgomery. The available ships and landing geography left the operation exposed at sea and on shore.