'Seaplane on the Min River.' In 1934 Pan Am bought two eight-seat Douglas Dolphins for its Chinese subsidiary. They served on a coastal route between Shanghai and Shantou, extended to Hong Kong in 1936. The Min River of Fujian province reaches the sea near Fuzhou and the photo was probably taken there, by a teacher or student of the Fukien Christian University. Photo from: Yale University Library

The USCG operated 13 Dolphins, 10 of which were the RD-4 variant. Photo by: Rudy Arnold / Smithsonian Institution

Coast Guard serial 131 changed to V126 in 1936. USCG aircraft were named after stars, such as Mizar, in this period. This RD-4 was still in service on 5 August 1941 when it struck a jutting rock near the Farallon Islands, off San Francisco. Three crew all killed. Photo from: US Coast Guard

Aircraft owned by William Boeing. The event is the first Western Canada Air Show in 1935 that was kicked off by an air race from Seattle to Vancouver. The event attracted many American entrants and visitors. Photo from: City of Vancouver Archives

What a wonderful place! The Wrigley family, the owners of Catalina Island, constructed this little seaplane airport and founded Wilmington-Catalina Airline in 1931 to fly in tourists from LA. For a literal quick turnaround, a wooden turntable was in use. The company bought the first two Douglas Dolphin amphibians. Its two Loening C-2s, in the background, were sold to Mexico in 1933.

The last Douglas Dolphin, now preserved at the naval aviation museum at Pensacola. Photo from: Civil Aviation Historical Society, Melbourne, Australia

Operated by the Australasian Petroleum Co. Donated to the Australian government in 1940 and taken in charge by the RAAF. Used for seaplane training as A35-1. Scrapped 1943.