During wartime, aircraft such as the Curtiss H-series certainly displayed their much sought after value. Their seaplane nature allowed them free use of water landings as needed while their inherent designs allowed for long "over-water" endurance. These qualities served well when hunting down enemy surface ships or submarines or in the locating of downed airmen or seamen. Patrols of such types were extremely common and seaplanes were also charged with hunting the slow and plodding Zeppelin airships. As control of waters between England and Europe was critical to Allied success in the war, seaplanes certainly played an important part in the ongoing struggle. Nearly all available Curtiss seaplanes used in World War 1 were operated by the British. American versions were limited to local use in anti-submarine patrolling though some arrived in Europe prior to the Armistice in November of 1918.