Both "Splendid" and "Spartan" were ordered to sail south for the Falkland Islands two days before the Argentine invasion of the islands on 30 March 1982. "Spartan" was the first boat to arrive in the islands and began to enforce a maritime exclusion zone imposed by the British. Shortly after, "Spartan" sighted Argentine merchant shipping mining the harbour at Stanley, but was not ordered to attack. This was partly due to British concerns about escalating the war too early, but also to avoid scaring off more valuable targets such as the Argentine aircraft carrier . Unlike , neither "Spartan" nor "Splendid" fired in anger during the Falklands War, but they did provide valuable reconnaissance to the British Task Force on Argentine aircraft movements and the submarines' presence effectively restricted the freedom of action of the Argentine Navy which spent most of the war confined to port.