AIM; The 1990 Hatherleigh Seismic Survey was programmed to obtain modern detailed and regional infill Vibroseis coverage of the Rivoli Trough. The major objective for licence Year 1 was to provide a detailed 1 km grid of dip lines across the Hatherleigh basement high mapped by earlier surveys. It was proposed to drill an exploration well on this feature later in 1990. Additional objectives included tying modern seismic to the Geltwood Beach 1, Lake George 1 and Beachport 1 exploration wells, besides obtaining further definition of weak leads observed on older seismic lines in the western, coastal portion of PEL 40. METHODS: Survey dates: 2/2/90 - 1/3/90. Energy source: Vibroseis. CDP coverage: 11 200%. Recording mode: 120 channel digital - Geocor IV recorder. VP interval: 25.0 metres, group interval: 12.5 metres. RESULTS: 11 lines totalling 186.5 line km were acquired by Party 205 of contractor Geosystems Pty Ltd, and processed by Halliburton Geophysical Services Inc. in Adelaide. Data quality for the semi-regional lines was variable, but the survey yielded some very good results from the tighter grid set over prospect areas. A firm drilling location for the licence Year 2 Hatherleigh 1 wildcat was selected at station 930 on line 90HA04 - the target is a stratigraphic pinchout of the Early Cretaceous Crayfish Formation on the southwestern margin of the Hatherleigh High.