Destroyer patrols on the Dover front

With German forces across the Channel and invasion barges visible in aerial photographs, Dover was as close to a surface-navy front line as Britain possessed in June 1940. Destroyers guarded coastal convoys and watched for a seaborne threat, especially at night. Day patrols invited air attack, while the watch-and-watch routine at night left crews with little sleep between sorties. Fatigue and uncertainty made identification difficult: friendly aircraft, the ship's own silhouette, or parachutes released by defensive rockets could all generate false alarms. One Dornier 17 went down nearby, and its surviving pilot insisted he would not be held long before someone reminded him that Canada was a long way away.