Dornier Do.24 flying boat

The Dornier Do.24 was a versatile three-engine flying boat primarily used by Germany (Luftwaffe) for air-sea rescue, reconnaissance, and transport in the Mediterranean, Baltic, and North Sea during WWII. Originally designed for the Netherlands, it also operated in the Dutch East Indies, Australia, Spain (until 1969), and France. 
 
Key areas of usage included:
Germany (Luftwaffe): Extensively used for air-sea rescue (Seenotstaffeln) in the Mediterranean, Black Sea, and Arctic.
Netherlands/Australia: Used for maritime patrol in the Dutch East Indies; six survivors were transferred to the Royal Australian Air Force for transport duties in New Guinea.
Spain: 12 Dutch-built units were delivered in 1944 for rescue operations, remaining in service until at least 1967.
France: Operated by the French Navy until 1952.
Sweden: One unit was impounded and used until 1952.