Coastal class airship

The Coastal Class (often known as the C-Class or simply the "Coastals") were a class of non-rigid airship or "blimp" used by the Royal Naval Air Service (RNAS) during World War I. The C-class blimp operated by the United States Navy after the war was a completely unrelated design. In total 35 Coastals were built, all at RNAS Kingsnorth, Kent. Entering service in 1916, the Coastal class remained in widespread service until 1918, with a few members of the class still in service at the signing of the Armistice, while others were replaced by the improved C-Star class as they became unfit for service. The blimps were used for long anti-submarine patrols in the Western Approaches and English Channel, protecting convoys from German U-boats. The Coastal class was one of the first aircraft types specifically designed to detect and attack submarines.