The Korean Attack Submarine program, KSS meaning Submarine, is a three-phased project to build up the Republic of Korea Navy (ROK Navy)'s attack submarine arsenal. Before the KSS program, the submarine fleet of the ROK Navy consisted of midget submarines, such as the Dolgorae class submarine and SX 756 Dolphin class submarine, which had limited capabilities for inshore operations. The KSS program sought to acquire submarines that can deter hostile submarines and surface ships; protect friendly naval bases and sea shores communications; carry out reconnaissance missions.