“The year 1945 saw WWII wind down and each of the armed services try to evaluate the implements they had fought with. The Navy concluded most of their aircraft had done well. By August 1945, the United States Navy was ostensibly the most powerful and modern in the world. Their flying boats had done well enough, but with the technology developed during the war, the Navy felt this class of aircraft could be greatly improved. What with the development of the turboprop engine and thin, high-lift wings, the Navy could increase payload, speed and effectiveness to a degree unheard of just a few years back.
In 1945, the Navy approached Convair to see what could be done and Convair came up with the Model 117. It was a very sleek, high wing boat with a single step hull, four Allison T-40 turboprop engines with six blade, contra-rotating props. Each engine developed 5,100 shaft horsepower (3,806 kW) and 830 pounds (376.48 kg) of jet thrust. The stabilizing floats were fixed, as there was no room to stow them in the thin, laminar-flow wing. The boat was named the “Tradewind”. It first flew in 1950 after a delay of some months because of trouble with the Allison engines. The Navy received it first Tradewind in 1954.”
Source: Aircrafthistory.com; Wiki