The term 'SHIP'S NAVIGATION SYSTEM' can be summarized as a system of navigation used on ships, specifically the LORAN system. LORAN stands for Long Range Navigation and is a hyperbolic radio navigation system that uses low frequency radio signals transmitted from fixed land-based radio beacons to determine the position of a ship. It was developed in the 1940s and was widely used until the advent of GPS in the 1990s.