Amphibious warfare are still operating. On completion they were towed across the English Channel by tugs to the Normandy coast at only 4.3 Knots (8 km/h or 5 mph), built, operated and maintained by the Corps of Royal Engineers, under the guidance of Reginald D. Gwyther, who was appointed CBE for his efforts. By 9 June, just 3 days after D-Day, two harbours codenamed Mulberry "A" and "B" were constructed at Omaha Beach and Arromanches, respectively. However, a large storm on 19 June destroyed the American harbour at Omaha, leaving only the British harbour still intact but damaged, which included damage to
Erwin Rommel at Calais. Although Hitler himself expected a Normandy invasion for a while, Rommel and most Army commanders in France believed there would be two invasions, with the main invasion coming at the Pas-de-Calais. Rommel drove defensive preparations all along the coast of Northern France, particularly concentrating fortification building in the River Somme estuary. By D-Day on 6 June 1944 nearly all the German staff officers, including Hitler's staff, believed that Pas-de-Calais was going to be the main invasion site, and continued to believe so even after the landings in Normandy had occurred. The 5 June storm in the channel seemed