The Germans tried to improvise.
The Engineer Battalion 47 of VII Army Corps was designated as having responsibility for the "construction of seaworthy ferries out of auxiliary equipment, local supply and bridging equipment". What was unusual in this was that this task, requiring a good knowledge of matters maritime, was tasked to this particular battalion - based in, and recruited from, Bavaria.
The engineers were nothing if not enthusiastic. They built rafts from pontoons, and were undismayed when half of these rafts sank while in harbour. Attempts to provide these rafts with power failed, because they broke up under the strain. Nonetheless, the Wehrmacht announced that these rafts would be towed behind the barges being towed by the tugs, and that the horses would be transported across the Channel on these rafts, saving the difficulties of loading the horses into the barges. One wonders what the horses would have made of this concept.
The engineers turned their attention to pontoons used for crossing rivers. Even the most optimistic observer had to regard this as a failure. The open pontoons filled with water and sank. The iron beams holding the pontoons together snapped in waves, and the exercise was discontinued.
One single main exercise was carried out, just off Boulogne. Fifty vessels were used, and to enable the observers to actually observe, the exercise was carried out in broad daylight. (The real thing was due to take place at night/dawn, remember).
The vessels marshalled about a mile out to sea, and cruised parallel to the coast. The armada turned towards the coast (one barge capsizing, and another losing its tow) and approached and landed. The barges opened, and soldiers swarmed ashore.
However, it was noted that the masters of the boats let the intervals between the vessels become wider and wider, because they were scared of collisions. Half the barges failed to get their troops ashore within an hour of the first troops, and over 10% failed to reach the shore at all. The troops in the barges managed to impede the sailors in a remarkable manner - in one case, a barge overturned because the troops rushed to one side when another barge "came too close". Several barges grounded broadside on, preventing the ramp from being lowered.
In this exercise, carried out in good visibility, with no enemy, in good weather, after travelling only a short distance, with no navigation hazards or beach defences, less than half the troops were got ashore where they could have done what they were supposed to do.
The exercise was officially judged to have been a "great success".