The intensity of Coastal Command's Swordfish operations was drastically increased following the German invasion of the Low Countries, expanding to involve four Swordfish-equipped squadrons. Typically flying from Detling, Thorney Island, North Coates and St Eval, Swordfish crews were dispatched to strike strategic targets off the coasts of Netherlands and Belgium on daylight raids, during which they were typically subjected to heavy anti-aircraft fire and interception by Luftwaffe fighter aircraft. Night time bombing raids were also conducted, attacking oil installations, power stations, and aerodromes. After the unsuccessful Battle of France and the signing of the French Armistice of 22 June 1940, Swordfish focused their activities against ports that were viewed as useful to a potential German invasion of the United Kingdom, which typically involved spotting for naval bombardments of such facilities as well as conducting security patrols.