The H.L.1 was exhibited uncompleted at the exhibition at Olympia in February 1914 fitted with a 1500NaN0 NAG C.II engine. It was ordered by the British Admiralty to be fitted with a 1600NaN0 Gnome engine and issued with serial number 105. The H.B.1 was launched in May 1914 but partly sank and was damaged due to being unbalanced. It was repaired and fitted with pontoon-floats and tested by Eric Gordon England without much success. It was not accepted by the Navy and was sold at auction in May 1915 for £30.[2]