EPP 10 was taken up by Shell in mid-1968 as high risk, potentially high reward frontier acreage over very deep water (200 to 2000 metres) in the Great Australian Bight outer continental shelf / continental slope region of South Australia. At that time drilling wells in such a locality was beyond the capabilities of available offshore drilling technology, but Shell were confident of attaining sufficient capability by the end of the 1970s. In the interim they intended to try to determine the hydrocarbon prospectivity of the permit, in conjunction with that of their adjoining EPPs 11, 5, 6 and 7, by utilising the best available geophysical and other remote sensing methods. The actual sole-risk programme of work followed by the company to satisfy its permit commitments was as follows: Permit Year 1 - 1339 line km of regional reconnaissance 24-fold reflection seismic data and some deep refraction profiles were obtained in the R 4 Marine Seismic Survey, using GSI's M/V Polaris; Permit Year 2 - 1103 line km of regional reconnaissance 24-fold reflection seismic data were obtained in the R 5 Marine Seismic Survey, using Western Geophysical's M/V Marchant III; - based on the new seismic work and other information, a regional geological review was performed to assess the area's sedimentation history and potential for hosting sizeable stratigraphic and structural hydrocarbon traps; Permit Year 3 - 783 line km of entrapment structure defining, semi-detailed 24-fold reflection seismic data were obtained in the R 6 Marine Seismic Survey, using GSI's M/V Dunlap; Permit Year 4 - based on processed and interpreted R 4, R 5 and R 6 surveys seismic data, a deep water acreage evaluation (seismic interpretation) report was written; Permit Year 5 - 884 line km of infill structural reconnaissance 24-fold and existing lead detailing 48-fold reflection seismic data were obtained from poorly covered EPP 10 areas where the water depth is greater than 1000 metres, in the R 8 Marine Seismic Survey, using GSI's M/V Eugene McDermott II; Permit Year 6 - 130 line km of semi-detailed 48-fold reflection seismic data were obtained over the principal identified leads located where the water depth is greater than 1000 metres, in the R 9 Marine Seismic Survey, using GSI's M/V Eugene McDermott II; - based on the R 8 and R 9 seismic work and preceding Shell interpretations, a deep water area seismic interpretation report was prepared; Permit Year 7 - based on geological information derived from Shell's drilling of the Platypus 1 and Potoroo 1 wildcat wells in nearby EPPs 6 and 5, a major seismic reprocessing exercise was undertaken for 930 line km of Shell's 1969, 1970, 1973 and 1974 seismic data in a regional grid over EPPs 10 and 11, aimed at better seismic stratigraphic delineation of units within the Cretaceous sedimentary section, so that useful palaeogeographic maps might be generated for play assessment; - 701 line km of detailed 48-fold reflection seismic data were obtained over three strong leads located where the water depth is greater than 1000 metres, to confirm closure and determine possible drilling locations, in the R 10 Marine Seismic Survey, using the Prakla-Seismos research vessel Prospekta; Permit Year 8 - further to the seismic reprocessing work, two summary Bight Basin study reports were written. One deals with the structural and sedimentological aspects of Shell's seismic reinterpretations, presenting isopachs and geological cross-sections showing Cretaceous depositional trends. A trend of paleotemperature vs dispersed organic matter content is also established for the Bight Basin. The second report discusses the stratigraphic and palynological findings of a petrographic study of 104 thin sections from the 3 wells drilled by Shell on the northern edge of the basin. It has enabled the division of the thick Bight Cretaceous sedimentary sequence into 6 seismically mappable units used by Shell to estimate the prospectivity of the 3 most significant leads in the permit area; - a final permit report was submitted with Shell's application to surrender EPP 10, summarising their evaluation of significant prospects in the permit at the stage of being finally committed to drilling one of them: this the company was unwilling to do for reasons of what was then perceived as unacceptable economic and geological risk.