The troops landed on the Cotentin Peninsula in Normandy, thus beginning to implement the Overlord plan. You might think there was no science involved. Actually, no: there is a record in Dwight Eisenhower's notebook dated 1944: “May 1, June 6, and June 19. These are the only appropriate days, as there is no full moon and a full tide.” Why was the military man and future politician and president so interested in synoptics? It was because the Americans needed the coast to be shallow. They brought special barges to the shore, “set” them on the bottom, and used them as piers for the landing of the main landing force. The high water could have hindered the implementation of these plans.