The Democratic Republic of Timor-Leste (East Timor) attained independence on 20 May 2002, marking its separation from Indonesia. As a newly independent country, East Timor is faced with a number of significant international opportunities, together with some obligations that it must fulfil, including the delimitation of its international boundaries. Similarly, for Indonesia, with 10 maritime neighbours, the delimitation of maritime boundaries is a significant challenge. This paper describes a preliminary study on the delimitation of the Indonesia – East Timor maritime boundary, with a focus on technical aspects. Geospatial data has been obtained from the Indonesian government and processed with the assistance of a specialised Geographic Information Systems (GIS) application: CARIS LOTS™. The main tasks are to simulate the maritime claims of Indonesia and East Timor, to identify overlapping claims and to delimit theoretical maritime boundaries between the two states. The United Nati...