AIM: To derive a clearer understanding of the morphology and structural style of the Robe Trough and its margins, and to detail structural leads identified within the central part of the trough, where a number of possible fault-bounded closures had been identified from existing seismic coverage. Leads in the survey area were selected for detailing on the basis of their proximity to the inferred hydrocarbon source kitchen, and also their location near a mapped basement flexure which has the potential to set up the required along-strike rollover. METHODS: Survey dates: 25/1/96 - 5/2/96. Energy source: Vibroseis. VP coverage: 20 000%. Recording mode: 400 channel digital - Geocor IV recorder. VP interval: 20.0 metres; group interval: 20.0 metres. RESULTS: 13 lines totalling 142.88 line km were acquired by Geo Systems Pty Ltd and processed by Robertson Research Australia Pty Ltd in Perth, WA. Data quality over most of the programme was fair to good. 52 downholes were drilled and recorded using weight drop by Velocity Data Pty Ltd, to determine the depth and average velocity of the weathered zone, and to allow reduction of the processed data to mean sea level datum. Interpretation of the Long Island data by the PEL 60 operator has confirmed that the onshore Robe Trough comprises a full graben with up to 7 km of sedimentary section. The graben is bounded to the north by the Trumpet Fault which extends offshore, while to the south it is bounded by the Lake Eliza Fault. Within the centre of the graben, an E-W trending uplifted zone has formed. The uplift appears to have commenced at the end of Crayfish Group deposition and is associated with some erosion and considerable crestal collapse. The normal faults comprising the crestal collapse zone are approximately E-W and define a mini-graben trend within the main graben. A number of fault-bounded structural leads are associated with this zone. Along the southern boundary of the trough there is considerable roll-over onto the downthrown side of the Lake Eliza Fault. This has set up one or possibly two four-way dip closures in the region. Mapping of basement and regional intra-Cretaceous reflectors has identified one mature prospect and two strong leads within fault-bounded closures developed along the sides of the central uplift zone. The Nunga Mia Prospect was recommended for drilling later in 1996.