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
Mulberry harbour Dundas & Whitson, Mowlem, Nuttall, Parkinson, Pauling & Co. and Taylor Woodrow. 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), assembled, operated and maintained by the Corps of Royal Engineers, under the guidance of Reginald D. Gwyther, who was appointed CBE for his efforts. Both locations for the temporary harbours required detailed information concerning geology, hydrography and sea conditions. To collect this data a special team of hydrographers was created in October 1943. The 712th Survey Flotilla, operated from naval base HMS "Tormentor" in