Development of the Seasprite had been initiated during the late 1950s in response to a request from the United States Navy, calling for a suitably fast and compact naval helicopter for utility missions. Kaman's submission, internally designated as the "K-20", was favourably evaluated, leading to the issuing of a contract for the construction of four prototypes and an initial batch of 12 production helicopters, designated as the "HU2K-1". Under the 1962 United States Tri-Service aircraft designation system, the HU2K was redesignated H-2, the HU2K-1 becoming the UH-2A. Beyond the U.S. Navy, the company had also made efforts to acquire other customers for export sales, in particular the Royal Canadian Navy; however, the initial interest of the Canadians was quelled as a result of Kaman's demand for price increases and the Seasprite performing below company projections during its sea trials. Due to its unsatisfactory performance, from 1968 onwards, the U.S. Navy's existing UH-2s were remanufactured from their originally-delivered single-engine arrangement to a more powerful twin-engine configuration.