The Shin Meiwa PS-1 followed the tradition of very successful Japanese flying boats of World War II, with a new name it was the post-war reconstitution of the Kawanishi company responsible for such legendary aircraft like the H8K 'Emily' which were superior to anything else in the world at the time. The PS-1 was a conventinal design with fixed strut mounted floats under the out wings as well as a T-tail and a retractable beaching undercarriage. It was powered by four license-built General Electric T64 turboprops with an additional fuselage mounted gas turbine to provide comprassed air for its boundary layer control system. With the role of anti-submarine warfare increasingly dominated by land-based patrol aircraft, the PS-1 was turned into a true amphibian search and rescue (SAR) platform with the removal of all its military equipment. These are still in use today with additional production scheduled for the forseeable future.

First flight of the prototype SS-1 took place on 5 October 1967 and delivered for service with the military designation PS-1. An improved development resulted in the SS-2A which was ordered without its operational equipment and armament as the US-1 SAR platform which over the course of its service life has saved over 500 lives. An ugraded version with new engines was later known as the US-1A.