The original H-Boat, HS-1 flew at Buffalo New York in 1917 powered by a 200 h.p. Curtiss engine which was replaced by a 360 h.p. Liberty engine.The first conversion to civilian use was done by an American firm, Aero Ltd. The next conversion was in Canada where a five place design, achieved by adding a side by side cockpit between the front cockpit and the pilot's cockpit, was adopted by the Air Board. In the belief that the extra load of a sixth place would seriously deteriorate the performance of the H-Boat no six place conversions were made in Canada.
The well known designation HS-2L is explained as: H for hydroplane, S for single engine, 2 for second version and L for Liberty engine. It was not a hot performer but it was available although described by some pilots as taking off, flying and landing at one speed of 65 m.p.h.
The Canadian Aero Film company received a contract from the Ontario government in 1920 to conduct an aerial survey of the province between Toronto and Moose Factory in James Bay. Between mid-August and late September Pilot W. R. Maxwell made five round trips in G-CAAZ including the first ambulance flight out of Northern Ontario with a patient suffering from mastoiditis. Other operators of the HS-2L aircraft were Central Canada Airlines, Canadian Airways, International Airways of Canada and the Laurentide Company. A consortium of paper companies with timber limits in the St. Maurice River valley of Quebec formed Laurentide which obtained the loan of two H-Boats from the Air Board. The flight of these planes from Halifax to Lac a la Tortue in Quebec was the first civil operation of an HS-2L. These planes provided the first aerial fire patrol and gave the first air to ground report of a bush fire. They also proved that the use of aerial photography was a valid and reliable method of identifying the type and value of a forest from the air. A new company, Laurentide Air Service Ltd. was formed in 1922 which continued the work of the flying boats, adding nine new boats to their fleet.
The decision of the Ontario government, announced in 1923, to establish its own air service was a serious blow to Laurentide resulting in the sale of thirteen of its HS-2Ls to that government. Another of their fleet was sold to Northern Air Services. In 1924 there was a major boom in the gold and copper fields of Northwestern Quebec which created a demand for a fast transport service from the rail head to Rouyn, Quebec. Laurentide Air Service responded to the demand with three weekly HS-2L return flights between Angliers, Lake Fortune and Rouyn which was the first scheduled air service in Canada. These flights were also the first regular airmail service in Canada, a concept that was so new the post office allowed Laurentide to issue their own 25 cent airmail stamps. Eventually air mail service was extended by connecting with trans-Atlantic steamers in the St. Lawrence River shortening the mail delivery by one to four days.
A glimpse of the future of bush flying occurred in October 1925 when men and equipment were urgently required in Red Lake before freeze up. Ground transportation was not able to provide service and no commercial operators were available, therefore, arrangements were made for the Ontario Provincial Air Service to carrry out the job - the only non-forestry operation of the service.
One of the OPAS fleet,G-CAOA, logged 2,251 hours over its nine years of active duty which is the greatest number of hours of any HS-2L. Although most of the H-boats were involved in the work of forestry, fire detection and suppression a few of them had more colourful experiences as rum runners during American prohibition. Others saw civilian service in China, Peru, Phillipines, Portugal, and the United States.