After World War II, aeronautical engineers in several countries sought to combine a very new aviation technology with a very old one. The former was the turbine (jet) engine; the latter was the seaplane.
In the United States the Navy sought to merge the technologies in jet-propelled flying boats for the maritime patrol and transport roles. Supported by seaplane tenders, such aircraft were envisioned as operating over vast areas without dependence on land bases. In 1945 the Navy invited aircraft manufacturers to propose flying-boat designs that would incorporate emerging technologies. The high speeds provided by jet engines were not vital to the maritime patrol role, thus Convair engineers adopted the turboprop engine for their next generation designs. The engine was essentially a turbine driving a propeller shaft to provide greater fuel economy, hence longer range, than a pure jet.