The Dolphin was built by Douglas Aircraft in 1930 as the "Sinbad," a pure flying boat without wheels. The Sinbad was intended as a luxurious flying yacht for America’s many millionaires but the Great Depression prevented any sales. Undaunted by the lack of demand, Douglas improved the Sinbad in 1931 so that it was amphibious, and could land on water or land. The improved aircraft was named "Dolphin", however this did not represent the end of development, as many more improvements were made, including an increase in the length of over a foot and several changes were made to the empennage, engine nacelles and wings. Douglas managed to attract the interest of the United States Coast Guard who not only bought the Sinbad, but 12 Dolphins and the success of the Dolphin helped the Douglas Aircraft Co. survive the Great Depression. The RAAF operated a total of four Dolphins: NC42186 (A35-1) operated in New Guinea on oil survey work with civilian operators until it was donated to the RAAF in June 1940; NC12212(A35-2) was operated by the Wilmington-Catalina Airline Ltd in the USA until purchased by the Australian Government; NC982Y (A35-3) was operated by the Crosley Radio Company in the USA until purchased by the Australian Government; and, NC14204 (A35-4) was operated by the Wilmington-Catalina Airline Ltd in the USA until purchased by the Australian Government. The Dolphin was only used as a stop–gap seaplane trainer and squadron hack at RAAF Base Rathmines until sufficient numbers of Catalinas were available. In service they proved difficult to maintain because of spares unavailability. Aircrew found them easy to fly and, given their ancestry, quite comfortable and spacious when compared to other seaplanes of the era. For details of the design, development and operational history of the Dolphin, including the many variants, click here, and for more on the history of the RAAF Dolphins, cick here. RAAF Dolphins
