On the night of 15 January 1962, in the Arafura Sea off the south coast of western New Guinea, Dutch warships and a patrol aircraft intercepted Indonesian motor torpedo boats that had come to land troops in the Dutch-held territory. One boat, the Matjan Tutul, was sunk, and Commodore Yos Sudarso, one of the most senior officers of the Indonesian navy, died with it. The Dutch call the action the Battle of Vlakke Hoek; in Indonesia it is known as the Battle of the Aru Sea. Accounts from the two sides differ on several points, and this article notes where they do.
A disputed territory
When the Netherlands transferred sovereignty to Indonesia in 1949, it kept western New Guinea apart, pending a later settlement. The question turned into a long dispute. On 19 December 1961 President Sukarno proclaimed Trikora, the People's Triple Command, to take the territory from the Dutch, and Indonesia began to send armed infiltrators across the sea.1
According to the Dutch historian Paul van der Steen in Historisch Nieuwsblad, four German-built motor torpedo boats left Jakarta for the east; one broke down on the way, and three went on and reached the Aru Islands. Antara names them as Matjan Tutul, Matjan Kumbang and Harimau, with Yos Sudarso aboard Matjan Tutul. The Indonesian news site Tirto writes that Colonel Sudomo, another of the operation's commanders, was aboard Harimau.2
The fight in the dark
The Dutch expected the attempt. Their naval intelligence had warned of it, and the destroyers Evertsen and Kortenaer were at sea, with a patrol aircraft overhead. Historisch Nieuwsblad says the aircraft picked up the boats on radar at around 8 p.m. local time. The aircraft dropped flares and tried to attack, but its flares and machine gun failed, and the boats fired back at it. Evertsen then opened fire.3
Matjan Tutul was hit and sank. Historisch Nieuwsblad says a shell struck its stern, where ammunition was stored, and the boat burned for about twenty minutes before going down. What happened to the other two boats is told in different ways. Historisch Nieuwsblad says the destroyers chased them and hit one, without saying more. Tirto and the Indonesian news agency Antara say both escaped.4
Indonesian accounts tell the story from the boats. Tirto, citing a biography of Yos Sudarso by Moh. Oemar, writes that he ordered the boats to turn back, that Matjan Tutul's engine then failed, and that it drew the Dutch fire so that the others could get away. Antara writes that he took his boat forward to draw the fire on purpose. Both report a last radio message from him urging his comrades to keep the fighting spirit burning.5
The dead and the captured
The figures differ. Historisch Nieuwsblad gives 39 Indonesian dead and 52 survivors pulled from the water by the Dutch. Tirto writes that 24 men went down with Yos Sudarso and that 53 survivors were taken prisoner. Tirto also writes that the boats were not armed for a sea fight.6
What followed
Militarily the operation failed, but it raised the pressure on the Netherlands. Historisch Nieuwsblad notes that it came less than two weeks after the Dutch government had announced talks with Indonesia, and that President Kennedy then urged both sides to negotiate. On 15 August 1962 the two countries signed the New York Agreement, under which the territory passed to a temporary United Nations administration and then, on 1 May 1963, to Indonesia.7
In Indonesia, 15 January is marked as Hari Dharma Samudera, a day of remembrance for the navy's dead, as Antara describes. Yos Sudarso was later declared a National Hero of Indonesia.8
