HMNB Portsmouth the military and naval units destined for Sword Beach on the Normandy coast as a part of Operation Overlord and the D-Day landings on 6 June 1944. Troops destined for each of the landing beaches left from Portsmouth aboard vessels such as the armed merchant cruisers HMCS "Prince Henry" and HMCS "Prince David", escorted by the Canadian destroyers HMCS "Algonquin" and "Sioux". The majority of the naval support for the operation left from Portsmouth, including the Mulberry Harbours. Boathouse 4 (built around the start of hostilities) contributed to the construction of landing craft and support vessels as well as more
390th Strategic Missile Wing On 25 May 1944, a detachment of the group was directed to bomb coastal defenses in France using radar, despite weather conditions that were ideal for visual bombing. Although crewmembers were not advised why radar bombing was directed, this mission was a test to determine if pathfinder operations would succeed if the weather over Normandy was foul when the invasion took place. Thereafter, the group would frequently use pathfinder techniques when clouds obscured its assigned targets. The group bombed the coast near Caen fifteen minutes before the D-Day landings in Normandy on 6 June 1944. It attacked enemy artillery in