High Quality Content by WIKIPEDIA articles! Operation Diver was the British codename for their countermeasures against the V-1 flying bomb campaign launched by the German Luftwaffe in 1944 against London and other parts of Britain. Anti-aircraft guns were redeployed in several movements: first in mid-June 1944 from positions on the North Downs to the south coast of England, then a cordon closing the Thames Estuary to attacks from the east. In September 1944 a new linear defence line was formed on the coast of East Anglia, and finally in December there was a further layout along the Lincolnshire-Yorkshire coast. The deployments were prompted by the ever-changing approach tracks of the missiles which were in turn influenced by the Allies' advance through Europe.