Battleships in World War II part of Operation Neptune, in support of the D-Day landings in June 1944. D-Day also saw the deliberate sacrifice of two old dreadnoughts ( and ), which were scuttled as part of the breakwater around the Allied Mulberry harbours. The sinking of "Prince of Wales" and "Repulse" off the coast of Malaya in 1941 demonstrated that even the most modern battleships could not hold off aerial attacks without decent aerial defenses. The British HACS fire control system had been rendered inoperable by the extreme heat and humidity of the Malaya tropical climate, and the anti-aircraft artillery had managed to shoot
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