The Dornier Do 18 was a development of the Do 16 flying boat. It was developed for the Luftwaffe, but Deutsche Luft Hansa received five aircraft and used these for tests between the Azores and the North American continent in 1936 and on their mail route over the South Atlantic from 1937 to 1939.
Dornier Do 18
The Do 18 D-ANHR in 1938.
Dornier Do.18 3-view drawing from L'Aérophile August 1936
The Dornier Do J Wal ("whale") is a twin-engine German flying boat of the 1920s designed by Dornier Flugzeugwerke. The Do J was designated the Do 16 by the Reich Air Ministry (RLM) under its aircraft designation system of 1933.
Dornier Do J Wal
N-24 landed on the ice at New Ålesund
Amundsen's Dornier Do J flying over the Oslofjord, 1925
A Wal at Slite, Gotland, on the Danzig-Stockholm route in 1925